SOWEEBY : ON NEW MARINE MOLL0SCA. 303 



Crtptodon Murchlandi, n.sp. PI. XXV, Fig. 13. 



Testa subtrigono-cordiformis, crassa, deprcssiuscula, aequivalvis, 

 insequilateralis, alba, pallide straminea, rugose irregulariter lamellata, 

 prope umbonem. laevis, lateribus divergentibus, iitrinque obtuse 

 angulata ; margo dorsalis arcuatus ; umbones acuti, incurvati, 

 antice locati ; margo ventralis late arcuatus ; area antica (sub- 

 umbonalis) concave depressa, rugose plicata ; cardo crassus, oblique 

 depressus, edentulus, sed infra rugosus ; pagina interna sordide alba, 

 corrugata ; impressiones musculares elongatse ; sinus pallii obliquus, 

 longus, linguaeformis. Long, (umbone ad raarg. ventralem) 41, 

 lat. 40 mm. 



Hob. — St. Vincent, Cape Verd Islands (Murchland). 



The form of this remarkable shell (of which I have only seen 

 two specimens) is veiy like that of C. flexuosus, Montagu, but on 

 a gigantic scale, and, unlike that very fragile little species, it is of 

 a solid substance, and particularly thick about the hinge. 



I adopt the name of Cryptodon (Turton, 1822), as the generic 

 position of the fossil Axinus (J. Sowerby, 1821) is very doubtful, the 

 hinge being unknown, and the name Thyasira was only given by 

 Leach in manuscript; although quoted by Lamarck in 1818, he gave 

 no description of it. Mr. Edgar A. Smith has pointed out that various 

 large species such as edentulus, usually called Loripes, should be placed 

 here, the type of Loripes being L. lacteus, Linn., which has cardinal 

 teeth, while all the Cryptodons are edentulous. 



DESCRIPTION OF PLATE XXV. 



Fig. 1. Conus Bougei, n.sp. 



2. ,, ,, var. /3. 



3. Cythara striatissima, n.sp. 



4. ,, optabilis, n.sp. 



5. Pkurotonia abbreviata, Reeve, var. Lifuensis, n.var. 



6. Mitra accincta, n.sp. 



7. Triphora etipunctata, n.sp. 



8. ,, fuscozonata, n.sp. 



9. ,, fuscoapicata, n.sp. 



10. Mormula excellens, n.sp. 



11. Area Fultoni, n.sp. 



12. Soletellina Hedleyi, n.sp. 



13. Cryptodon Murchlandi, n.sp. 



