438 CRETACEOUS GASTROPODA 
have internally on the posterior part of the dorsal side two longitudinal ridges. 
It remains to be shown in what connection these ridges are with the organization 
of the animal, and it is not improbable that further generic distinction is here 
indicated. 
2. Antale, Aldrovandus, 1642 (De testaceis, Lib. III, cap. V, p. 282), ? Hnta- 
lium, Defr., 1819. The animal appears to be similar to that of Dentalium, but the 
shell is tubular, generally much prolonged, smooth, the posterior end has the 
margin entire, the internal tube slightly projecting, and usually with a roundish 
opening. .; 
The English smooth Antale vulgare of daCosta (D. Tarentinum of Lamarck) 
or Dent. duplex, Desh., and Dent. ambiguum, Chenu, may be considered as typical 
species of this genus. Aldrovandus was the first who proposed a distinction between 
the longitudinally ribbed and the smooth Dentalia, calling the latter Antale, but 
I cannot trace the name Antalis, as adopted by H. and A. Adams in their Genera 
for species belonging to the next genus. 
The name Zntalium* was proposed by Defrance (Dict. sc. nat., vol. XIV, 
p- 517) for a species from the Maestricht Chalk, Pyrgopolon Mose, Montf., which 
he called Ent. rugosum. This species appears to agree in its general character- 
istics with Antale, being smooth or slightly rugose, with the margins of the 
posterior aperture roundish, entire, and usually with an internal tube which more 
or less projects. On account of this internal, supplementary tube, which most 
probably owes its origin to the embryonal shell, it being retained in subsequent 
growth as likewise in many other genera of the Dzwvrazmp#, Defrance proposed 
for the Maestricht species the name Zxtalium. How in most of the Concho- 
logical works the idea of applying the name Zvtaliwm to such species as have 
the posterior end fissured has been introduced I am unable to trace out just at 
present, and it is of little consequence, as the name itself cannot be used in the 
sense in which Defrance proposed it. 
Should the Maestricht species prove to be generically distinct from Anéale, 
it must either be called, according to Montfort, Pyrgopolon (or, according to 
Konig, Pharetrium, the type of the last being Ph. fragile, Kénig)—(see Chenu’s 
Conch. Illustrations). Dentalium clava, Lam., would be another species of Pyrgo- 
poton, and I suspect that the genus has to be placed in the eapizrvZ. 
3. Entalis, Gray,t 1840 (Antalis, H. and A. Adams, Gen. I, p. 457, ea parte ? 
non id. Aldrovandus). Shell tube-like, slightly curved, longitudinally ribbed or 
sometimes striated, gradually tapering towards the posterior end, which has the 
margin on the ventral or convex side provided with a short and broad fissure. 
The type of this genus is the Dentaliwm entale of Linné, as emended by Forbes 
and Hanley in their Brit. Moll. II, p. 450. Chenu in his Conchological Illustrations 
* Not idem, Linné; Scheuchzer called the Dent. elephantinum also an Entaliwm. 
+ Sowerby (1842) is usually quoted as the author of this genus. It is really difficult to determine whether 
Gray or Sowerby used the name first. Sowerby’s name bears the date of 1842, but Gray’s Synop., Brit. 
Museum, was published in 1840, though Gray himself adds to his name the date 1844—see Proceed. Zool. Soc., 
London,,1847, p. 158, 
