58 PROCEEDINGS OF THE ACADEMY OF [Vol. LXXIV 



(1910), and that of another specimen 41 is given here (Plate VI, fig. 

 26). As Pilsbry has already pointed out, this radula is truly 

 helicinid in character. Although possessing certain marked, indi- 

 vidual peculiarities, in others it forms a connecting link between the 

 Vianinae and the Helicininae. 



The A-central is heavy and has a single, large, outer hook 

 which makes it superficially resemble that of Lucidella. The, 

 B-central has three heavy cusps and somewhat resembles that of 

 the more primitive species of Eutrochatella. The comb-lateral 

 has only 3 large cusps, and the heavy outer process is more like 

 that of the Vianinae than like any of the preceding genera. Never- 

 theless, in general shape it is distinct, and more closely related 

 to the Helicininae. The accessory plate is small and heavy and has 

 an inner projection which fits behind the outer end of the comb- 

 lateral. The anterior edge is slightly reflected and must act as a 

 rather efficient brace to the comb-lateral. The inner 14 marginals 

 are unicuspid, although the base is broad, as in all of the 

 Helicinidae. 



While the description of the radula of the type species throws 

 light on the relationships of the genus s. s., the other groups need 

 examination. As pointed out under Lucidella, it is very probable 

 that other distantly related small species have been included in 

 the genus, as a whole. Since Chitty's description of the many 

 species and "genera", the group seems to have received very little 

 attention. 



Table IV. Radular Formulae in Stoastoma, Eutrochatella, 



Viana, and Calybium. 



Centrals. Comb Marginals Grand 



ABC Lateral 123 Total Total 



S. visum 13 4 3 14 6 53 117 



E.erythraea 3 3 4 8-9 10 2 3 46 103 



E.mestrei 3 3 4 8 17 5 64 139 



E.jugulata 3 3 4 10 13 58 127 



E.chrysochasma 3 3 4 7-9 12-14 (Troschel) 50+ 111 + 



E. s. politula 3 3 3-4 4-5 13 5 45 101 



E.pyramidalis 3 3 4 5 11 44 99 



/:. rupestris 3 2-3 14 5 35 81 



E. sloanii 1 20 10 56 123 



E.remota 1 24 80 171 



41 1 dried specimen; A. N. S. P. no. 15236; collected in Garrett's Woods, near 

 Mandeville, Jamaica, by A. P. Brown (1910). 



