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47 



4. Descriptions of Thirty-four New Species of Bivalve 

 MoLLUscA (Leda, Nucula, and Pythina) from the Cu- 



MINGIAN COLLECTION. By ArTHUR AdAMS, F. L. S. ETC. 



1. Pythina ARCUATA, A. Adams. 



P. testą transversa, elongata, ineeąuilaterali, triangulari, latere 

 antico breviore, subtruncato, ad umbonibus angulato, postico lon- 

 giore, rotundato ; margine ventrali arcuato, in medio sinuuto, 

 irregulariter Mante ; alba concentrice striata, epidermide fusca 

 radiatim striata induta. 

 Hab. Isle of Zebu, adhering to LinguJa anatina at the upper 

 edge, sandy mud, 3 fathoms. Mus. Cuming. 



This is an arcuated triangular species with the anterior side of the 

 valves angulated, and the surface covered with a fuscous epidermis 

 striated towards the ventral margin. 



2. Pythina Ctjmingii, A. Adams. 



P. testą tenui, elongato-transversa, subtrigonali, cequilaterali, um- 

 bonibus acutis medianis, epidermide tenui virido-fusca induta, 

 concentrice striata, radiatim sidcata, suleis ad marginein ven- 

 tralem distinctioribus, umbonibus Icsvigatis, corrosulis, margine 

 ventrali in medio sinuato, intus inciso-crenulato. 

 Hab. Gindulman, Isle of Bohol, sandy mud, 8 fathoms ; Him- 

 mamailan, Isle of Negros, sandy mud, 3 fathoms. Mus. Cuming. 



This is the largest species of Pythina yet known, the transverse 

 diameter being about oue inch. The shell is thin, nearly smooth, 

 and covered with a brownish-green epidermis, and with the surface 

 oear the beak eroded. 



3. Pythina paula, A. Adams. 



P. testą parva, transverso-elongata, trigonali, ceąuilaterali, adum- 

 bones subangulata, latere postico angustiore, antico rotundato ; 

 concentrice striata, albida, epidermide tenui fulvicante induta ; 

 margine ventrali sinuato, in medio excavato. 



Hab. Raimes Island, Torres Straits {Capt. Ince). Mus. Cuming. 



This is a small whitish species angulated near the beak and covered 

 with a thin, pale yellowish epidermis. 



4. Pythina peculiaris, A. Adams. 



P. testą parva, transverso-elongata, cequilaterali, triangulari, 

 flexuosa, alba, concentrice striata, umbonibus minutis, medianis 

 acutis, latere postico plica angidata obliqua instructo, margine 

 ventrali medio valde sinuato. 

 Hab. Ceylon {E. L. Layard, Esq.). Mus. Cuming. 

 This species is of a very remarkable form, being shghtly twisted 

 laterally, and so deeply sinuated in the ventral margin as to appear 

 bent on itself. 



5. Pythina triangularis, A. Adams. 



P. testą parva, cequilaterali, trigonali, alba, in medio linea impressa 



