A Revision of Snakes of the Genus Conophis (Family Colubridae, from Middle America)

by John Wellman

Subcaudals.—The number of subcaudal scutes varies from 55 to 89. In some populations there is no overlap in the range of variation of males and females. The total variation and sexual dimorphism are analyzed in table 3.

Size and Proportions

Although considerable variation in size is observable, little taxonomic use is made of size since sufficient series are not available to determine age classes. The subspecies attaining the largest size is C. lineatus concolor; all others are smaller and of about the same size and proportions. The longest specimen, a male of C. l. concolor, has a body length of 893 mm., a tail length of 274 mm., and a total length of 1167 mm.

Table 2.—Variation in the Number of Ventrals in Conophis.

Taxon	Number of Specimens	Range	Mean	Standard Deviation	Standard Error	Coefficient of Variation
l. concolor	45	158-170	163.7	1.56	0.23	0.95
l. dunni	36	159-178	167.2	4.56	0.76	2.72
l. lineatus	26	157-169	163.5	3.59	0.72	2.20
nevermanni	6	173-183	176.5	4.00	1.63	2.27
pulcher	26	149-180	169.5	5.31	1.04	3.13
vittatus	171	149-180	163.7	6.33	0.15	3.87

Table 3.—Sexual Dimorphism as Indicated by Variation in the Number
of Subcaudals in Conophis

Taxon	Sex	Number of Specimens	Range	Mean	Standard Deviation	Standard Error	Coefficient of Variation	Coefficient of Difference
lineatus concolor	♂	22	68-74	70.3	2.14	0.46	3.04
								1.97
	♀	16	56-65	61.8	2.18	0.55	3.53
lineatus dunni	♂	14	67-80	74.5	3.86	1.03	5.18
								0.95
	♀	16	60-72	67.1	3.91	0.97	5.82
lineatus lineatus	♂	11	67-73	69.8	6.17	1.85	8.84
								0.60
	♀	9	60-66	62.4	6.17	2.06	9.89
nevermanni	♂	3	82-89	85.3	……	……	……
								……
	♀	2	71-76	73.5	……	……	……
pulcher	♂	7	70-79	74.3	3.11	1.17	4.19
								0.93
	♀	11	65-71	68.2	3.42	1.08	5.01
vittatus	♂	95	59-76	67.8	3.33	0.34	4.91
								1.28
	♀	58	55-66	60.0	2.75	0.36	4.58

Color Pattern