GASTEROPODA. 139 



4. Adeorbis subcarinatus. Mont. Tab. XV, fig. 8. 



Helix subcarinatus. Mont. Test. Brit. p. 438, t. 7, fig. 9, 1803. 

 Trochus subcarinatus. Brown. Conch. lUust. p. 51, fig. 16-17, 1827. 



— RUGOSUS. Brown. Wem. Mem. ii, 520, t. 24, fig. 5, (Flan.) 

 CiNGULA SUBCARINATA. Flem. Brit. An. p. 305, 1828. 

 Delphinula trigonostoma. Bast. Bord. foss. pi. 4, fig. 10, 1825. 

 Adeorbis subcarinatus. S. Wood. Catalogue 1842. 



Trochus trigonostomus. Ni/st. Coq. foss. de Belg. p. 385, pi. 35, fig. 23, 1844. 

 Natica SUBCARINATA. Phil. En. Moll. Sic. vol. ii, p. 141, t. 24, fig. 13, 1844. 



J. Testa j)usind, orbicuiafo-dejjressd, sjnrd brevi ; anfradibus trihus ; subtus jjlanatis ; 

 longitudinaliter Uneatis, et transversim cingulatis ; cinguUs elevatis ; aperturd magnd 

 subtetragond ; umbilico Into. 



Shell small, thick, and strong, with three whorls rapidly enlarging, flattened 

 beneath, covered with four elevated ridges, one of which is in the centre of the base ; 

 obliquely crenulated between the ridges ; aperture large, subquadrangular ; outer lip 

 curved and expanded ; umbiUcus large and deep. 



Diameter, ^ of an inch. 



Locality. Cor. Crag, Sutton. 



Red Crag, Sutton. Recent, Britain. 



This shell is rare in ray cabinet. I have no doubt of its identity with the recent 

 British species, and the figures above referred to are presumed to be the same. 

 Our shell has four distinct ridges — three on the upper part of the whorl, at unequal 

 distances, and one upon the centre of the base, with a large and patulous mouth of 

 a somewhat quadrate form, deeply sinuous on the inner side, with an incipient canal 

 both at the upper and lower angles of the mouth ; the upper one raising the shell 

 slightly at the suture, which gives a depression on the volution. 



5. Adeorbis pulchralis. 8. Wood. Tab. XV, fig. 4. 



Margarita helicixa. S. Wood. Catalogue 1842. 



A. Testd minutd, tenui, pellucidd Q), depressd, suborbicidari, /leliciformi ; anfractibm 

 tribm, superne convexis, subtus planiusculis, transversim tenuissime striatis ; aperturd 

 patente, obtuse angulato ; umbilico magna, prof undo ; peritremd acuta, superne incurvd 

 proviinente, intus et infra valde sinuatd. 



Shell small, thin, and probably pellucid in the recent state ; depressed and sub- 

 orbicular, heliciform, very finely striated along the volutions ; volutions three, rapidly 

 increasing ; convex above and rather flat beneath, obtusely angidated on the outer 

 edge ; aperture large and wide, somewhat angular, with a large and deep umbilicus ; 

 peritreme sharp, slightly interrupted by the volution, curved, and projecting on the 

 upper side, and deeply sinuated on the inner margin. 



Diameter, i of an inch ; altitude, l the diameter. 



Locality. Cor. Crag, Sutton. 



