42 2 MONOTOCARDIA GYMNOGLOSSA RACHIGLOSSA chap. 



Fig. 279. — Carinnria mediterranea Lam., Naples: 

 a, anus ; br, branchiae ; /, foot ; i, intestine ; 

 m, month ; p, penis ; s, sucker ; sh, shell ; I, 

 tentacles. x i. 



a very small spiral shell. Carinaria (Fig. 279) has a rugose 

 translucent skin, visceral sac sub-median, apparently peduncu- 

 lated, covered by a capuliform shell. The larval shell, which 

 persists in the adult, is helicoid. 



Fam. 2. Atlantidae. — Shell spiral, operculate, covering the 



animal. Branchiae in a 

 dorsal cavity of the mantle ; 

 foot trilobed, with a small 

 sucker on the mesopodium. 

 The shell of Atlrmta is 

 discoidal and sharply keeled, 

 while that of Oxygyrus is 

 nautiloid, with the spire 

 concealed, no keel, aperture 

 dilated. 



(c) Gymnoglossa. — Ea- 

 dula and jaws absent ; pro- 

 boscis prominent, sexes prol)al)ly separate, penis present. The 

 section is probably artificial and unnecessary, the families com- 

 posing it being, in all probability, Taenioglossa which have lost 

 their radula in consequence of changed conditions of life (pp. 

 79, 225). 



Fam. 1. Eulimidae. — Proboscis very long, retractile, mantle 

 forming a siphonal fold ; shell small, long, subulate, polished ; 

 suture shallow, aperture continuous, operculum present or absent. 

 Animal often parasitic, sucking the juices of its host by its long 



pro1)OScis. Trias . Genera : J^ulima (subg. Suhularia, Arcu- 



ella, Apicalia, Mucronalia, Stiliferina, and others), StUifer, 

 Scalenostoma, Niso, and HojAoipteron. 



Fam. 2. Fyramidellidae. — Tentacles auriform, proboscis as in 

 Eulinddae, a prominent mentum or flap under the buccal orifice ; 

 shell usually small, conical ; suture shallow, apical whorls (the 

 embryonic shell) sinistral (p. 250), operculum corneous, pauci- 



spiral ; nucleus excentrical. Trias . Genera : Pyrami- 



deUa (subg. Syrnola, Otoijleura, Chrysallida, Mumiola), Odostomia, 

 Eulimella, MurchisonieUa, Turhonilla (subg. Dunheria and 

 Cingulina). 



{d) Eachiglossa (p. 220). — Proboscis long, retractile ; siphon 

 distinct, radula without uncini, sometimes without laterals ; teeth 

 strongly cusped ; shell generally wholly external. 



