154 MOLLTTSCA FROM THE CRAG. 



prominent, with the upper part of the volution somewhat projecting, giving the 

 outer lip a straighter form than in the other species ; the inner lip or columella is 

 somewhat oblique, flattened, and narrower than in the preceding species, with a 

 less regularly ovate aperture ; the outer lip is less curved, giving a slightly angular 

 form to the opening. 



Some of my specimens are very imperfect; more and better materials are 

 required to determine the species. From its difference of form I have presumed it 

 to be new, though its present name may be considered only as a provisional one. 



Capulus,* Be Montfort, 1810. 



Patella (spec.) Linn. 

 Peleopsis. Lam. 1815. 

 Amalthea. Schutn. 1817. 

 Actita. Fisch. (Hermansen.) 

 Pilopsis. Konig. 

 Brocchia. Bronn. 

 Aceoculia. Phillips. 

 Cyrtholithes. Vanuxem. 



Gen. Char. Shell obliquely conical, with a broad expanded base, and a slightly 

 recurved apex ; aperture large, generally elliptical, sometimes circular ; muscular 

 impressions united posteriorly ; rounded and enlarged in front, with an opening 

 between them for the head of the animal ; in a recent state, covered with a thick 

 epidermis. 



This genus is well distinguished from Patella by the position of the apex, which 

 is situated on the posterior part of the shell, and is generally a little recurved, 

 whereas, in Patella, it is on the anterior, and is simply conical ; the muscular im- 

 pressions, or rather impression (for the two are united into one ligulate band), is 

 therefore on the posterior part, with an opening between the obtuse terminations, 

 for the egress of the animal's head, and is joined behind under the apex. Species 

 from the Palseozoic Rocks have been formed into a genus by Phillips, under the 

 name Acroculia, in consequence of an obliquity in its recurved apex, which character 

 alone is insufficient for generic distinction, and from the excessive variableness of 

 some of my Crag fossils, such character may be almost doubted as sufficient for 

 even specific determination. 



* Etym. (?) Capulus, a handle. 



