) 



/ 



REPORT ON THE LAMELLIBRANCHIATA. 137 



trifle more in front than behind. Tiie beaks are small, a little raised above the hingu- 

 line, incurved, rosy at the tips, and situated at about a quarter of the whole length 

 from the anterior extremity. The teeth are small, erect, and much approximated. The 

 interior is whitish, and exhibits two broad pale rosy red rays towards the upper part. 

 The anterior muscular impression is oval, acute at both ends, the hinder being larger 

 and rounder. The pallial sinus is large, broad, deep, extending to the centre of the 

 valves, obliquely truncated at the end, the upper corner of the truncation being rounded, 

 and the lower one sharply rectangular. 



Length 17^ mm., height 13, diameter 8^. 



Habitat. — Station 212, south of the Philippine Islands, at a depth of 10 to 20 

 fathoms ; sand. 



This species probably attains larger dimensions than those given above. It is 

 distinguishable on account of its fine striation and the peculiar distribution and tone of 

 its colouring. 



Cytherea phasianella, Deshayes, approaches it in form, but is a little broader in front 

 and ixiore acuminate posteriorly. Cytherea roseotincta is, however, readily distinguished 

 by its finer strife, difierent painting, slighter hinge, and larger muscular scar at the 

 hinder end. 



Cytherea (Caryatis) rostrata, Koch. 



Cytherea rostrata, Koch, Philippi's Abbild., vol. i. p. 150, pi. i. tig. .3. 



Cytlwrma rostrata, Sowerby, The.s. Concb., vol. ii. p. 633, pi. cxxxiii. lig. 122. 



Diane rostrata. Reeve, Conch. Icon., vol. xiv. fig. 41. 



Cytherea (Caryatis) rostrata, Romer, Monog. Venus, vol. i. p. 90, pL xxiv. figs. 3-36. 



Venus tehuelcha, d'Orbigny, Yoy. Amer. M^rid., vol. v. p. 5.56. 



Habitat. — Station 321, off Monte Video, in 13 fathoms; mud. 



M. d'Orbigny was probably in error in stating that Philippi's locality " Brazil " was 

 not correct for this species. He himself found it at St. Bias on the coast of Patagonia, 

 and now I record it from Uruguay, so there is every reason to conclude that it ranges 

 still further north as far as South Brazil. The pallial sinus is at times shorter and 

 broader than in the specimen figured by Romer, and the form of the shell is higher in 

 proportion to the length. The following measurements of an extreme example will 

 illustrate this. 



Length 39 mm., height 37^. 



(ZOOL. CHALL. EXP. — PART XXXV. — 1885.) Mm 18 



