VALVATA SINCERA. 



DESCRIPTION. 



ANIMAL. Head whitish, above with a tinge 

 of slate-colour, increasing posteriorly; mouth 

 pale yellowish; tentacles filiform, whitish, more 

 than 0.2 inch long; eyes minute, black and 

 shining, situated on the upper and outer part of 

 the posterior side of the protuberance at the 

 base of the tentacles: margin of the branchial 

 cavity blackish-brown; pinnatifid branchia semi- 

 transparent, consisting of a stem, on each side 

 of which extend at right angles filiform obtuse 

 branches bent in zigzag, shorter towards the 

 extremity, about 10 on each side, the whole re- 

 sembling a feather; tentaculiform branchia rather 

 longer than the tentacles, equally slender, and 

 obtuse: foot whitish, swelling, and regularly 

 rounded posteriorly, with the anterior lobes 

 sharply angular, and the middle somewhat con- 

 tracted. Adams, in letters. 



SHELL "globose-discoid, obsoletely striate, 

 brownish-green; whorls three and a half, accu- 

 rately rounded, rapidly enlarging to the aper- 

 ture; suture deeply impressed; spire but little 

 elevated; apex obtuse; umbilicus deep, about 



