NE.ERA. 51 



as Corbula Waelii; and the figures wliicli he also gave 

 are very exact. This Avas in 1843. The great French 

 work on the expedition to the Morea was published 

 eight years previously. Bory St. Vincent contributed 

 the geological portion of this work, which contains a 

 good representation of the shell ; the only other notice 

 of it appears in the index to the plates, where it is 

 entered as " C costellata, Deshayes.^'' It is the N. sul- 

 cata of Loven, C. rostrato-costellata of Acton, and Tel- 

 Una naticuta of Chiereghini. The figures in Philippics 

 work on the Sicilian Testacea are not satisfactory ; they 

 were probably made up or " restored,^'' for he says that 

 all his specimens were " paullulum leesas.^^ 



3. N. rostra'ta^, Spengler. 



My a rostrata, Spengl. in Skrivt. Selsk. iii. p. 42, t. 2. f. 16. 



Shell resembling a fig with a broad stalk, nearly equivalve 

 except in the young, convex, more solid than the preceding 

 species, opaque and almost lustreless : sculpture, numerous 

 but slight concentric raised striae or wrinkles, becoming more 

 crowded and flexuous towards the posterior side; the upper 

 angle on that side (which forms a long and diagonal crest or 

 ridge, extending from behind the beak in each valve to the 

 rostral point, and defined by an oblique rib) is crossed by 

 close-set and somewhat curved striae at a right angle to the 

 transverse markings on the body of the shell : colour whitish : 

 epidermis more persistent than in the other two species, pale 

 yellowish -white : margins rounded on the anterior side and 

 immediately in front, bending upwards and nearly in a straight 

 course to the deep sinus or indentation caused by the exten- 

 sion of the posterior side ; this part is remarkably twisted and 

 elongated, being about two-fifths of the entire breadth of the 

 shell ; posterior dorsal margin curved inwards ; anterior dorsal 

 margin high-shoiddered : beaks inflected ; umbones rather 

 prominent ; dorsal excavation deep, wide on the anterior and 

 narrow on the posterior side : cartilage small, golden-yellow, 



* Beaked. 



D 2 



