Narrative of travels and discoveries in Northern and Central Africa, in the years 1822, 1823, and 1824

by Dixon Denham; Hugh Clapperton; Walter Oudney

Hab. cum antecedentibus.

The notch at the anterior extremity of the hinge being always acute, never obtusangular or rounded, I have confined myself to it in the distinctive character of this species, which differs in several other respects from Anodon purpureus and rugosus of Swainson, to both of which it is, however, nearly related. The size of the shell, in the several specimens before me, varies from 1½ by ¾ of an inch to 3 inches by nearly 1½. Its form is transverse-oval, with a slight slope at the anterior end. The hinge margin is straight. Epidermis olive-green, appearing of a reddish-brown colour, owing to the pink colour of the surface underneath, which latter in one specimen passes into bluish-green at the umbones. Muscular impressions three; one of them, at the anterior end, oval, and continued in a faint tapering form towards the hollow of the umbo; of the two other impressions, which are both stronger marked, the one nearest to the edge of the valve is oval, with a small rounded sinus at the inner border, and close to it a smaller irregularly oval mark with notched margin: the two principal marks are connected by the edge of the impression of the mantle, the smaller mark being placed within the line. The tinge of the internal surface is pink, imperfectly painted over as it were with white. The several specimens, in different stages of growth, exhibit all these characters; there is, however, among them a single valve of rather larger dimensions and more rounded than the rest, with a fine bronze-coloured internal surface like that of Iridina nilotica. Whether this is to be considered as a distinct species, or only as a variety indicative of the full grown state of the shell, I must leave to the decision of conchologists more experienced in discriminating the ambiguous species of this genus.

---

No. XXIV.

Thermometrical Journal kept at Kouka in Bornou.

Date.		Winds.	Fah. Thermometer.
			6 a.m.	Noon.	3 p.m.
March 1823.
	15	E.N.E.	70	98	103
Sunday,	16	S.S.E.	75	95	102
	17	S.S.E.	78	99	104
	18	E.N.E.	77		104
	19	S.E.			98
	20	E.N.E.	78	95	101
	21	N.E.	82	100	105
	22	E.N.E.	80	97	100
Sunday,	23	N.E.	78	90	94
	24	N.E.	79	94	97
	25	E.N.E.	79	97	101
	26	E.N.E.	79	100	103
	27	E.N.E.	79	101	103
	28	E.N.E.	82	97	98
	29	E.N.E.	80	97	100
Sunday,	30	N.E.	80	94	97
	31	E.N.E.	80	94	96
April.
	1	N.E.	77	98	101
	2	N.E.	80	95	100
	3	S.E.	80	99	101
	7	N.E.	80	99	102
	8	N.E.	80	99	103
	9	E.N.E.	78	98	102
	10	E.N.E.	77	97	99
	11	N.E.	72	100	100
	12	N.E.	78	104	107
Sunday,	13	N.E.	84	100	105
	14	E.N.E.	82	100	105
	15	N.E.	87	103	105
	16	E.N.E.	86	95	105
	17	E.N.E.	87	99	106
	18	E.N.E.	86	103	109
	19	N.E.	88	102	106
Sunday,	20	E.N.E.	87	102	107
	21	E.N.E.	85	100	100
	22	E.N.E.	86	102	103
	23	E.N.E.	85	102	103
	24	N.E.	83	101	103
	25	E.N.E.	85	103	102
	26	N.E.	85	103	103
Sunday,	27	N.E.	86	102	102
	28	N.E.	83	101	103
	29	E.N.E.	81	103	103
	30	E.N.E.	82	103	103
May.
	1	E.N.E.	85	106	106
	2	N.E.	85	103	105
	3	N.E.	83	105	98
Sunday,	4	E.N.E.	81	99	99
	5	E.N.E.	82	95	96
	6	E.N.E.	81	102	102
	7	N.	86	104	103
	8	N.E.	71	99	96
	9	N.E.	81	99	96
	10	N.E.	85	95	94
Sunday,	11	N.E.	86	101	95
	12	Calm.	81	99	95
	13	W.S.W.	75	98	98
	14	W.S.W.	75	95	98
	15	W.S.W.	74	97	97
	16	W.S.W.	72	92	95
	17	S.W.	74	97	98
Sunday,	18	W.S.W.	74	96	99
	19	W.S.W.	73	96	99
	20	W.S.W.	76	95	99
	21	W.S.W.	74	102	100
	22	W.S.W.	73	100	100
	23	W.S.W.	84	104	101
	24	S.W.	76	96	96
Sunday,	25	S.W.	73	96	96
	26	S.W.	81	98	100
	27	S.W.	76	99	100
	28	S.W.	80	98	99
	29	W.S.W.	81	97	102
	30	W.S.W.	82	100	102
	31	W.S.W.	80	100	102
June.
Sunday,	1	W.S.W.	76	97	97
	2	W.S.W.	80	97	96
	3	W.S.W.	81	99	99
	4	W.S.W.	81	99	100
	5	W.S.W.	80	99	100
	6	S.W.	80	98	98
	7	S.W.	75	95	100
Sunday,	8	S.W.	78	98	98
	9	S.W.	79	95	97
	10	S.W.	78	89	90
	11	W.S.W.	75	89	93
	12	W.S.W.	79	87	95
	13	W.S.W.	80	95	95
	14	W.S.W.	81	97	97
Sunday,	15	W.S.W.	82	99	97
	16	W.S.W.	81	97	96
	17	W.S.W.	81	99	101
	18	W.S.W.	80	97	99
	19	W.S.W.	79	89	93
	20	W.S.W.	78	92	93
	21	W.S.W.	77	92	95
Sunday,	22	W.S.W.	78	98	99
	23	S.W.	81	95	87
	24	S.W.	76	95	87
	25	S.W.	80	97	96
	26	S.W.	81	94	95
	27	S.W.	87	96	98
	28	S.W.	81	97	92
Sunday,	29	S.W.	82	96	97
	30	S.W.
July.	1	S.W.	82	97	99
	2	S.W.	81	92	92
	3	S.W.	82	93	94
	4	S.W.	74	85	84
	5	S.W.	78	89	94
Sunday,	6	S.W.	78	89	96
	7	S.W.	78	89	91
	8	S.W.	78	90	92
	9	W.S.W.	81	87	92
	10	W.S.W.	77	92	95
	11	W.S.W.	75	85	97
	12	S.W.	75	85	88
Sunday,	13	S.W.	71	79	82
	14	S.W.	72	82	89
	15	S.W.	75	83	90
	16	S.W.	76	87	90
	17	S.W.	72	84	93
	18	S.W.	76	83	89
	19	S.W.	75	86	90
Sunday,	20	S.W.	74	87	89
	21	S.W.	72	83	86
	22	S.W.	73	84	87
	23	S.W.	73	86	89
	24	S.W.	74	84	90
	25	S.W.	73	83	87
	26	S.W.	71	84	86
Sunday,	27	S.W.	80	86	89
	28	S.W.	76	86	90
	29	S.W.	73	84	87
	30	S.W.	76	85	95
	31	W.	76	85	92

Date.		State of Weather.			Fah. Thermometer.
					6 a.m.	Noon.	3 p.m.
1823.
Aug.	1		Rain all night.		75	82	86
	2				73	78	79
	3		Sunday. Rain in evening.		74	80	82
	4				78	82	83
	5				76	82	84
	6		Rain much.		73	77	78
	7				74	78	81
	8		Rain.		76	80	81
	9				75	81	82
	10		Sunday. Rain, loud thunder.		74	77	80
	11				76	81	83
	12		Rain and thunder all night.		79	83	85
	13				75	80	81
	14				76	80	85
	15		Rain, thunder, vividlightning.		77	84	87
	16				76	82	85
	17		Sunday.		78	83	85
	18				77	84	86
	19		Rain and thunder during thenight.		79	85	86
	20		Rainy day.		78	84	85
	21				75	82	83
	22		Much rain.		74	79	83
	23		Morning cloudy.		74	80	84
	24		Sunday. Drizzling rain.		76	83	85
	25		Night violent.		75	77	79
	26		Night.		75	78	79
	27		All night.		74	78	79
	28		Day and night, showers.		73	77	79
	29		Rain.		74	78	80
	30				75	80	82
	31		Sunday. Rain, much thunder.		74	78	80
Sep.	1				74	79	81
	2				76	84	86
	3				79	85	89
	4				80	85	88
	5		Morning. Rain and thunder.		80	80	81
	6				78	83	84
	7		Sunday.		78	85	86
	8		Rain.		79	80	81
	9				78	83	85
	10		Night, hurricane, east.		80	86	88
	11		South.		78	85	87
	12				80	86	88
	13				79	85	87
	14		Sunday.		78	86	89
	15				80	86	89
	16				81	87	89
	17		Cloudy afternoon.		81	88	89
	18				80	85	87
	19		Hurricane, east and a half south.Strong 3 p.m.		80	87	85
	20				80	84	87
	21		Sunday.		78	85	87
	22				79	87	89
	23				78	86	88
	24				80	88	90
	25				82	89	92
	26		Violent storm, noon wind N. hailand rain.		80	89	90
	27				76	86	89
	28		Sunday.		80	86	88
	29				81	87	91
	30				80	86	91
Oct.	1		Rain and wind in night.		80	87	91
	2				78	84	85
	3				80	85	88
	4		Wind, thunder.		81	87	90
	5		Sunday, rain and wind.		80	86	88
	6				79	87	89
	7				80	88	90
	8				80	89	93
	9				79	89	92
	10		Breeze N.W.		78	89	91
	11				77	90	92
	12		Sunday,		79	92	94
	13				78	92	94
	14				79	91	93
	15				77	92	93
	16				83	92	94
	17				81	92	94
	18				80	90	93
	19		Sunday,		81	92	94
	20				79	92	94
	21				80	92	94
	22				81	93	95
	23				75	90	92
	24				76	85	88
	25				77	87	90
	26		Sunday,		77	88	91
	27				78	90	92
	28				78	90	91
	29				79	91	93
	30				78	88	90
	31				79	89	92
Nov.	1				78	87	90
	2		Sunday,		76	89	91
	3				75	88	89
	4				76	88	90
	5				77	87	89
	6				77	88	90
	7				76	87	90
	8				75	86	88
	9		Sunday,		76	88	90
	10				77	86	89
	11				79	87	88
	12				76	88	90
	13				74	87	89
	14				74	86	88
	15				73	87	89
	16		Sunday,		74	88	89
	17				74	83	86
	18				75	85	87
	19				75	86	88
	20				75	85	87
	21				75	86	88
	22				69	78	81
	23		Sunday,		71	79	81
	24				69	77	79
	25				68	78	80
	26				67	79	81
	27				66	78	80
	28				65	77	79
	29				66	77	79
	30		Sunday,		67	79	80
Dec.	1				66	79	81
	2				67	78	80
	3				66	79	81
	4				65	78	80
	5				67	80	82
	6				68	80	82
	7		Sunday,		68	78	80
	8				63	76	78
	9				64	76	78
	10				63	75	77
	11				64	76	78
	12				64	77	78
	13				64	78	78
	14		Sunday,		63	75	77
	15	⎧ ⎪ ⎪ ⎨ ⎪ ⎪ ⎩	Dull cold days. WindN.N.E. and E., but a cloudy sun at noon.	⎫ ⎪ ⎪ ⎬ ⎪ ⎪ ⎭	64	74	76
	16				63	75	77
	17				64	75	76
	18				63	74	76
	19				63	72	74
	20				63	71	72
	21		Sunday,		64	73	75
	22				65	74	75
	23				66	73	75
	24				65	74	76
	25				66	74	77
	26				64	75	76
	27				64	72	74
	28		Sunday,		65	73	75
	29				64	74	76
	30		N.E. cold.		61	63	65
	31				58	66	73
1824.
Jan.	1				61	74	76
	2				60	71	72
	3				61	72	73
	4		Sunday,		60	70	74
	5				61	73	75
	6				63	75	77
	7				65	77	79
	8				65	82	84
	9				66	84	86
	10				65	83	85
	11		Sunday,		64	82	84
	12				65	83	85
	13				66	84	86
	14				66	85	86
	15		Elephant,		70	85	87
	16				75	86	87
	17				74	85	86
	18		Sunday,		75	87	89
	19				75	90	91
	20				74	87	89
	21				75	88	90
	22				74	86	87
Mar.	2				80	94	96
	3				77	94	95
	4				78	95	97
	5				78	95	96
	6				80	95	97
	7		Sunday,		79	96	98
	8				80	95	96
	9				79	91	93
	10				79	92	94
	11				78	93	95
	12				79	92	94
	13				78	94	96
	14		Sunday,		80	95	97
	15				82	95	98
	16				80	94	96
	17				79	93	95
	18		Winds south.		79	92	94
	19		Heavy dull sky.		78	91	93
	20				79	93	95
	21		Sunday,		79	94	96
	22				78	93	95
	23		North breeze.		75	90	92
	24				76	89	91
	25				77	90	91
	26				78	94	97
	27				80	95	99
	28		Sunday,		83	99	101
	29				85	99	102
	30				84	98	100
	31				85	99	100
Apr.	1				86	97	99
	2				85	94	96
	3				84	95	96
	4		Sunday,		79	93	95
	5				84	96	100
	6				86	99	101
	7				87	98	100
	8		Slight rain with lightning.		86	100	104
	9				90	101	104
	10				87	99	102
	11		Sunday,		88	100	103
	12				86	102	105
	13				87	103	105
	14				86	101	103
	15				87	101	102
	16				86	100	103
	17				85	100	104
	18		Sunday,		86	101	105
	19				84	101	103
	20				85	100	105
	21				86	100	106
	22		N.W. wind,		86	100	100
	23				85	100	102
	24		Thick atmosphere.		86	102	103
	25		Sunday,		79	99	102
	26	⎫ ⎬ ⎭	Violent N.W.winds.	⎧ ⎨ ⎩	86	103	103
	27				86	102	102
	28				83	102	103
	29				80	102	103
	30				82	103	103
May	1				86	104	106
	2		Dull and thick, with wind.		83	100	104
	3	⎫ ⎪ ⎬ ⎪ ⎭	Rain, Thunder.
	4			⎰ ⎱	83	100	100
	5				81	100	100
	6
	7				86	98	100
	8				85	99	101
	9		Sunday,		87	99	102
	10				88	99	101
	11				87	97	99
	12				89	99	101
	13		First day of summer.		88	99	106
	14				80	99	104
	15				81	100	104
	16		Sunday,		86	100	104
	17				84	99	100
	18				86	100	102
	19				87	101	103
	20				88	102	104
	21				86	100	104
	22				85	99	104
	23		Sunday,		86	98	104
	24	⎫ ⎪ ⎬ ⎪ ⎭	Sun rises at 5. 10.and the day is 13h. 10m. sets 6. 10.	⎧ ⎪ ⎨ ⎪ ⎩	88	101	102
	25				87	100	103
	26				88	100	104
	27				87	101	103
	28				88	102	103
	29		Morning, thick hot vapours.		89	101	102
	30		Sunday. Night stormy, norain.		91	100	101
	31				88	98	100
June	1				90	101	102
	2				89	99	102
	3				90	103	105
	4				90	102	104
	5		Dull.		89	103	104
	6		Sunday,		88	102	103
	7				87	101	102
	8				88	99	100
	9				89	100	102
	10				87	98	99
	11				87	97	100
	12		Wind S.S.E.		89	99	102
	13		Sunday,		88	100	104
	14				89	100	104
	15				90	101	103
July	19				80	87	90
	20				78	87	89
	21		Much rain.		79	88	90
	22		Dull.		80	86	86
	23				80	90	95
	24				79	89	91
	25		Sunday,		80	91	92
	26				80	90	92
	27				78	88	90
	28				79	87	91
	29				78	88	92
	30				80	89	91
	31				80	89	90
Aug.	1		Sunday,		81	92	96
	2				81	93	95
	3				80	90	91
	4				78	87	90
	5				79	89	92
	6		Sultry. Aide kebir.		80	94	95
	7		Night, rain.		81	91	93
	8		Sunday,		78	84	87
	9				79	88	90
	10				80	89	90
	11				79	88	90
	12		Much rain.		80	89	90
	13				78	80	82
	14				79	81	83
	15		Sunday,		76	82	81

---

Thermometrical Journal kept at Kano.

Date.		Winds.	Fah. Thermometer.
			6 a.m.	Noon.	3 p.m.
January 1824.
Sunday,	25	E.N.E.	83	84	84
	26	E.N.E.	82	84	84
	27	N.E.	64	79	79
	28	N.E.	65	80	80
	29	N.E.	74	75	76
	30	N.E.	74	76	76
	31	N.E.	72	75	76
February.
Sunday,	1	N.E.	80	82	83
	2	N.E.	73	79	79
	3	N.E.	69	79	80
	4	N.E.	70	79	78
	5	N.E.	79	83	83
	6	E.N.E.	79	82	84
	7	E.N.E.	81	84	84
Sunday,	8	N.E.	79	84	84
	9	N.E.	75	79	80
	10	N.E.	77	80	80
	11	N.E.	74	74	74
	12	N.E.	70	73	73
	13	N.E.	69	73	74
	14	N.E.	72	74	74
Sunday,	15	N.E.	72	76	76
	16	N.E.	74	82	83
	17	N.E.	74	84	84
	18	N.E.	81	85	86
	19	N.E.	82	87	87
	20	N.E.	81	85	86
	21	E.N.E.	82	86	87