OF SOUTHERN INDIA. 443 
26. Dent. Geinitzianum, Ryckholt, has been proposed for a species considered to be identical 
with Dent. medium figured by Sowerby apud Fitton, but Sowerby says that the figure of D. medium 
in the Min. Conch. is a bad one of the same species, as the one figured in the Transactions, aud this 
appears very probable. Ryckholt, however, says that they are both distinct, and that the description 
in the Min. Conch. is perfect. Unless the originals have been examined Ryckholt’s decision must 
be accepted only conditionally. There is, however, no reason to be given why two similar but still 
distinct species ought not to occur at Tournay. 
7. Dent. septangulare, Fleming, is doubtful. 
8. Dent. celatulum, Baily, is a Dentalium. 
9. Dent. Rotomagense. 
10. Dent. lineatum, Guéranger (Album pal., 1867, pl. 14, fig. 36) is apparently a true 
Dentalium and closely allied to D. nutans, Kner. 
Dent. deforme, Lamck. in Guéranger’s Album pal., pl. 16, fig. 37, must most probably be 
referred to the SERPULIDZ, 
P11. Dent. cidaris, Geinitz, appears to be closely allied to Dent. Rhodani, P. and Roux. 
?12. Dent. (alternans, Ryckholt), 1852 (non zd. Miiller, 1850) only differs from the last species 
by having the shell very slightly curved, though Geinitz said, when he first (Char. II, p. 74) 
described the Dent. cidaris, under the name of Dent. striatum, that the shell is slightly curved 
or straight. 
18. Dent. Michauxianum, Ryckholt, may be an Antale, but judging from its cylindrical form 
it can also belong to Fwustiaria ; the posterior end of the shell not having as yet been observed 
perfect. 
14. Dent. bicostale, Ryckh., probably an Antale. 
15. Dent. glabrum, Geinitz, is an Antale or a Fustiaria. 
15a. Dent. glabrum, Geinitz apud Miller, Monog. Petref. Aachner Kreide, 1851, pt. II, p. 5, 
is a Fustiaria, having a slit of about 3 inch long at the ventral side. 
16-18. Dent. polygonum, Rss., Dent. laticostatum, Rss., and Dent. nutans, all belong to Dentalium. 
19. Dent. Sacheri, Alth. The shell of this species is smooth like an Antale; no mention 
is made in the description of the existence of a posterior slit, but the figure seems to show a long 
and very narrow fissure as characteristic for Fustiaria, 
20. Dent. multicanaliculatum, Giimbel (Geogn. Besch. Bayer. Alp., p. 572) appears to be 
closely allied to Dent. nutans, Kner, but of larger dimensions. 
21. Dent. rugosum, Miller, may belong to Antale. 
22. Dent. alternans, Miiller, apparently a true Dentalium, and not unlike the D. nutans 
of Kner. 
23. Dent. nudum, Zek., belongs probably to Fustiaria. 
24-25. Dent. Nysti, Binkh., and Dent. planicostatum, Heb., appear to belong to Dentalium, as 
restricted. 
26. Dent. Mose, Montf., has either to be placed in the genus Antale or form the type of the 
genus Pyrgopolon. 
27. Dent. (erdaris, Geinitz) in Miiller’s Monog. Petref. Aach. Kreidef. Suppl., 1859, p. 20, 
pl. 8, fig. 6, appears to differ from the true Dewt. cidaris by its much compressed form and 
want of intermediate thinner ribs. 
28. Dent. notabile, Kichw. (Leth. Ross., XI livr., 1867, p. 800, pl. 28, fig. 1) is probably 
an Antale. 
The same author also mentions as occurring in the cretaceous rocks of Russia, Dent. ellipticum, 
Sow. (which is known to be a cast of D. decussatum, Sow.), Dent. glabrum, Geinitz, Dent. striatum, 
Sow. (= Dent. cidaris, Geinitz?), and Dent. medium, , 
