D. Calypso J. Hall, vol. VII, pl. XI A. fig. 21 p. 66 »Postero-lateral pits, moderately strong and elongate». There are casts of the two well distinct maculæ.
D. caudatus Brünn.
a. Forbes and Salter in British Organic remains, Dec. II pl. 1, fig. 3 give a good figure, showing the oblique pitlike maculæ. On page 2 is told that »a pair of lateral strong indentations indicate a second furrow above» (»the transverse furrow between the tip»).
b. Salter, pl. 3, figs. 7, 8, bad figures, the description verbally the same as above. What Angelin pl. VIII, fig. 2 c gives as the hypostoma of »Ph. caudata» is in fact the hypostoma of a species of Lichas.
D. Mac Coyi Barr. Supl., pl. 13 f. 32. This magnificent hypostoma belongs to the same group as D. micrurus Hall as to which we may hesitate whether there not be a double pair of maculæ above each other near the posterior border. In this species, however, there is the transverse lower groove and above probably the two maculæ united by a groove so closely as to resemble the lower groove.
D. micrurus J. Hall, Pal. N. Y. III pl. 74 fig. 20. Shows, as it were, a double pair of maculæ, very like D. spinifer Barr.
D. rugosus Barr. pl. 24 f. 23. The two maculæ in the ordinary place, without being united by a groove.
D. socialis Barr. pl. 26 f. 21. Rather of an uncommon shape, not so triangular as in the other species, the two maculæ distinct as narrow slits. P. 553 »Vers l'extrémité du corps central, on aperçoit de chaque côté, près du bord, une impression oblique, alongée et arquée».
D. spinifer Barr. Pl. 25, fig. 20. A large beautifully preserved hypostoma, shows what I think we positively must interpret as a double pair of maculæ close above each other. As stated above there is reason to believe that in other species of Dalmanites there also are indications of four maculæ, though not so evident as in this species. Barrande says nothing about this remarkable feature.
Dalmanites imbricatulus Angelin.