810 MESSRS. MELVILL AND STANDEM ON [Nov. 13, 



and concentric lamellse ai'e stronger proportionately. Within, the 

 surface is quite smooth. 



Pecten townsendi Sowb. 



Pecten tovmsendi G. B. Sowerby, Proc. Malac. Soc. Lond. vol. i. 

 p. 216, pi. xiii. fig. 10 (1894). 



P.G. Off Mussandam, on the telegraph-cable at 50 to 55 

 fathoms, and in several other places in the Gulf, unparticularised. 



I. Karachi, found at very low tides amongst rocks. From 

 this locality came the type, now in the collection of Mr. J. J. 

 Mac Andrew. 



A magnificent species, allied to P. crassicostatus Sowb. and 

 P. nohilis Reeve, known by its zigzagged and vaiiegated style of 

 painting. 



Pecten (Yola) DOROTHEiE Melvill, sp. n. (Plate LIY. fig. 1.) 



P. testa magna, suhorhiculata, aiquilaterali, incequivalvi, solichdd; 

 valva dextra multum convexa, sinistram omnino siqyerimpen- 

 dente, sinistra ipsa concava ; costis radiantibus 17-18 utraque 

 valva prcedita, his dextrce valvce plus minus Icevibus, albo- 

 carneis, nitidtolis, longititdinaliter leniter bi- vel toHstdcidosis, 

 interstitiis sub lente transversivi squamo-liratulis, ad latera 

 spiraliter rubro paucistrigata, illis sinistrce valvce, simul ac 

 interstitiis, arctissime concentrice striato-liratis , st(,pe7-Jicie omni 

 fusco-rubescente, concava, versus umbonem solum Icevi, nitida, 

 hie illic sparsim proicipue ad umbonem, lineis fidgetrinis nigro- 

 rufis irregidariter ornata, costis quam in dextra angustioribus ; 

 auricidis fere ceqihalibus, latis ; pagina interna alba, nitida, 

 versus umbones solum pallide ochracea. 

 Alt. 50, lat. 57, diam. 20 mm. 

 Hab. P.G. Dabai. 



Chiefly characterised by the smoothness of the right valve, the 

 ribs being already cut into deep interstices, slightly 2-3-sulcate, 

 Avhile the fellow-valve is concave, dark nnicolorous fuscous-red, 

 smooth ; and the equally smooth umbo, in the neighbourhood of 

 which are zigzag sharply-drawn lines of dark brown, few in number. 

 The whole of the surface of this valve is clea.rly concentrically 

 striate -lirate ; the auricles are subequal. 



Allied to P. jacobceus L., sinensis Sowb., and heptpelianus Sowb. 

 I am much indebted to Mr. G. B. Sowerby for having examined 

 this new form, and given his pronouncement thereupon. Named 

 in honour of my youngest daughter, Dorothea Melvill. 



Pecten (Yola) filosus Reeve. 



P.G. Kharag Island ; 3 fathoms, sand. Gulf of Oman, Maskat ; 

 10 fathoms, muddy sand. 



Pecten (Yola) pyxidatus Born. 



P.G. Gulf of Oman, MaJcolm Inlet (Kubbat or Ghobat 

 Ghazira). Single valves only, at 24-26 fathoms. Maskat; 15 

 fathoms, perfect but young. 



