SIPHON ARIA. 



153 



Fig. 254. 



Hermannsen uses the name Sijihonaria in preference to Liria, 

 Gray 



The Siplwnarise are marine, being found adhering to rocks 

 between tide marks ; they have a widely extended geographical 

 range, but are most numerous in the tropics. 



Siplioiiaria alternata, Say. — Shell conical, witli upwards of 

 thirty obsolete, hardly raised, unequal ribs ; apex obliquely curved, the 

 tip pointing nearly in a parallel direction with the sur- 

 face of the shell, and acute ; color brown, radiated with 

 white ; base oval. Breadth three-tenth inch. 



Inhabits the southern coast of East Florida. 



It seems to approach the leucopleura, as described by 

 authors, excepting that the base is not ovate, as the 

 base of that shell is said to be. (Sny.) 



Patella alternata, Say, Journ. Acad. Nat. Sc. V, 215 



(1S26) : ed. Bjnney, 124. 

 Siphonaria alternata, Say (1832), Am. Conch. IV, pi. xsxviii : Binney's 



ed. p. 192, pi. xxxviii ; ed. Chend, 50, pi. xiii, f. 3. 



I have not seen this species. Fig. 254 is copied from Say's 

 figure. 



Siplionaria o^qniilirata, Carpexter. — Shell sub-conic, oval, 

 regular, radiately ornamented with numerous subrugulose, equal ridges, 

 the interstices being narrow and smooth ; dark olive, 

 ridges high ; epidermis thin, adherent ; internal surface 

 dusky, hardly iridescent ; edge creuulated ; canal sub- 

 central, scarcely showing exteriorly. Length .83, breadth 

 .57, height .3. 



One specimen of beautiful growth in the Mazatlan col- 

 lection agrees with a larger but somewhat irregular, one 

 In that of Mr. Cuming, in characters which appear to 

 separate it from all varieties of S. lecanium. Riblets equal, 

 interstices smooth, channel nearer the middle and not con- 

 spicuous either by swelling or special marking outside. 

 The Mazatlan specimen has much broader interstices than 

 that of Mr. Cuming ; but as the riblets are bifurcating, it is probably not 

 fully grown. There is no trace of striulas. The examination of more 

 specimens may possibly merge it into the polymorphous S. lecanium, from 

 the extreme variety of which the non-prominence of the canal appears to 

 separate it. (Carpenter.) 



Siphonaria srquilirata. Carpenter, Maz. Cat. 184. — Reeve, Con. Icon. 15. 



Fig. 255. 



Gulf of California. Mazatlan. Fig. 255 is copied from Reeve. 



