1906.] SOLEXID.E FROM ZANZIBAR. 857 



adductor muscle to the postei'ior edge of the pi-oximal portion of 

 the siphon is greater, though the retractor pedis posterior muscle 

 is shorter. The retractor pedis anterior muscles are a little 

 shorter and their bifurcations are hardly discernible. The free 

 portion of the siphon is large, the inhalent chamber being much 

 larger than the exhalent one. The siphonal valves are also 

 strongly developed. The length of the free portion of the siphon, 

 however, cannot be ascertained as a part of it is missing. The 

 distal is deeper than the proximal half of the foot, and moi'e 

 resembles that of Ensis ensis. Regaixling the alimentary canal 

 there is relatively a, greater difFei'ence. The oesophageal and 

 cardiac divisions are smaller. The central division (or cavity 

 receiving the small bile-duct) is situated more antei-iorly. The 

 pyloric division is largei-. The caecum of the crystalline style is 

 situated on the ventral side of the stomach, and the distal portion 

 of it gradually curves towards the doi-sal surface of the pedal 

 cavity. The intestine leaves the stomach more anteriorly, makes 

 a number of loops in and anteiiorly to the liver, and passes to the 

 distal end of the caecum of the crystalline style before I'eturning 

 along the right lateral side of the same. — H. H. B. 



It is with some hesitation that I have detei-mined the single 

 specimen at hand as belonging to Solen aclnaces of Hanley. It 

 a,grees in regard to the genei-al curve of the shell and the anterior 

 ti-uncation and posterior end of the valves, also in respect of the 

 colour and periostracum. It is smaller than the type, being only 

 2 inches in length and 11 millims. in breadth, and, at this age, 

 looks rather more slender. However, having only a single 

 shell to judge from, it is impossible to say whether this apparent 

 slenderness would prove to be a constant character. The uncei-- 

 tainty of the ideiitification is increased by being unable to compare 

 it with the type of the species, which is only known to me by the 

 description and figure. Mr. Orossland observed that the foot, in 

 life, was flat and tongue-shaped, and that by rapid beating of it 

 fi'om side to side, the animal swam round a basin in which he had 

 placed it so actively, that the siphonal or posterior end of the 

 shells protruded from the water. — E. A. S. 



Solen sloanii Gray. 



Solen sloanii Gray, MS. Brit. Mus. ; Hanley, Cat. Biv. Shells, 

 1843, pp. 12 and 336, pi. xi. fig. 18; Sowerby, Conch. Icon, 

 vol. xix. pi. iii. fig. 10; Hedley, Proc. Linn. Soc. IST. S.Wales, 

 vol. xxiv. p. 432 (notes on animal). 



Solen versicolor Philippi, Abbild. vol. iii. p. 43, pi. ii. fig. 3 

 (1848). 



Solen philippimms Dunker, MSS. ; Sowerby, Conch. Icon, 

 fig. 13. 



Hcd). Wasin I., lOfath. {Crossland) ; Port Jackson (' Challenger'). 



One valve only. — E. A. S. 



57* 



