234: CRETACEOUS GASTROPODA 
last volution. The Sc. ornata, Baily (Quart. Journ. Geol. Soc., Lond., 1855, XI, 
p. 459, pl. 12, fig. 2), from South Africa is extremely like, but differs in having 
the spiral striation also more uniform, and comparatively finer. 
Localities. —Shutanure, E. of Anapaudy, N. of Alundanapuram, and N. of 
Serdamungalum, in brownish or greyish sandstones; not very common. 
Formation.—Trichinopoly group. 
XXIV. Famnily,—CACIDA. 
H. and A. Adams’ Genera I, p. 355, and others, 
Dr. Gray’s classification of the Caczp#, immediately after the Rrssorpa, is 
well supported by forms, like Shkenea and others, the animals of which, as likewise . 
the young shells, are exceedingly similar in form. Viewing, however, other 
apparently more closely related families to both these two, it would seem more 
suitable to place the Cacrp# after the Turrrretzrpa, or at least in close connection 
with the same. Clark (Brit. Hist. Moll., p. 323) notes specially the great simi- 
larities in the organisation of Cecum, Vermetus, and Turritella. 
Deshayes in his recent edition of the Paris fossils (Vol. II, p. 278,) introduces 
Cuvier’s name of TUBULI-BRANCHIATA, as a sub-order, for this and the following 
two families, which he admits only as genera in his family TuBIsprRATA. Cuvier’s 
name refers to a certain form of the gills, which, however, are not in any 
particular way differently formed from those of the Turrrrerzm# and others. 
On the contrary, Mr. Deshayes’ arguments in favor of the TUBULI-BRANCHIATA 
refer chiefly to the irregularities and to the adhering of the shells to foreign 
objects, the small or rudimentary foot, united sexes and other characters, which 
merely depend upon the mode of living. If these ought to form the characters of 
Cuvier’s sub-order, it is evident, that the Czczp# must be excluded from it, inas- 
much as they are mostly free ;—at least in their full grown stages of age.* The 
animals have the foot terminating with a small creeping disc, and move with the 
assistance of the long head almost as quickly as do the Assiminee. It would be, 
therefore, rather inconsequent and at the same time unjustifiable to admit the 
so-called genus Cecum into Deshayes’ proposed family Tusrsprrata, which cannot 
replace the three families which we adopt here, namely, Czcrpm, Verurrips#, and 
SILIQUARIIDA. 
Carpenter in his admirable Monograph of the Czcrp# (Proc. Zool. Soc., 
Lond., 1858, p. 4138, etc.,) proposed in this family four genera :— 
1.— Cecum, Fleming, 1817. 
2.—Brochina, Gray, 1857. 
3.—Weioceras, Carpenter, 1858. 
4.-—Strebloceras, Carpenter, 1858. 
* It is only supposed by Mr. W. Clark, (Hist. Brit. Moll., p. 325), the first observer of the animal of 
Cecum, that they are probably attached when young. See also Gray’s Guide, 1857, p. 101. 
