OF CONCHOLOGY. 181 



perpendicular and transverse stria;, and coarse perpendicular 

 wrinkles, some of which are scarcely to be distinguished from 

 the ribs, of which there are ten, well developed, crenellating 

 either margin. 



Lingual membrane similar to that of the typical B. oblongua, 

 as figured by Heynemann, in Malac. Blatt., 1868. 



A specimen from Tobago, received by Mr. Robt. Swift from 

 Governor Rawson, furnished the jaw and lingual membrane here 

 described. 



BuLixMUS PAKDALIS, Fe'r. (Dn/ptus.) 



Jaw thick, long, low, slightly arcuate, of almost equal height 

 throughout ; ends but slightly attenuated, blunt ; whole anterior 

 surface occupied by twelve stout, broad ribs, denticulating either 

 margin. 



Museum Comparative Zoology. 



Bulimus marmoratus, Dunker. (Dryptus.) 



Lingual membrane long and broad ; teeth as usual in the 

 genus, the marginals a simple modification of the laterals, with 

 two small, blunt denticles. 



Limicolaria Numidica, Reeve. 



Jaw thin, highly arcuate, smooth, ends attenuated. 



The specimen examined is preserved in the Museum of Com- 

 parative Zoology, at Cambridge. 



Bulimulus aureolus, Guppy. var. Rawsoni. 



Lingual membrane similar to that of B. laticinctus, described 

 in Ann. N. Y. Lye, X, 81, PI. ii., as follows : 



" Lingual membrane long, and quite broad in comparison to its 

 length, composed of numerous waving rows of teeth. Centrals 

 subpyramidal, the base excavated, apex not pointed, but bluntly 

 rounded and recurved into a stout, obtuse, long cusp, which is 

 unequally divided into two blunt, stout lobes. Laterals very 

 much longer and larger than the centrals, long, narrow, obliquely 

 recurved into a greatly developed unequally trilobed cusp. Mar- 

 ginals but little modified from the laterals in shape, but narrow, 

 denticulated on the outer side of their reflected cusp, which is 

 bicuspid rather than trilobed." 



Gov. Rawson, Tobago. 



Bulimulus alternatus, Say. (Thamaslus.) 



The lingual membrane of a Texan or Mexican specimen was 

 described by us in L. & Fr. W. Shells, Part I, p. 203, fig. 351. 



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