42 MR. A. WHITE ON NEW CRUSTACEA. [JaU. 22, 



This species is most like the young of T. gangeticus ; but the 

 dorsal spots are solid, not annular; and the head is olive, dotted 

 with black. 



It has some affinity to Trionyx tuberculatus of Dr. Cantor from 

 Chusan, which appears, from a drawing by Dr. Cantor in the Indian 

 Museum at Fifehouse, to be distinct from any of the other Asiatic 

 species that have occurred to me. That species has eight large and 

 four small white-edged black spots, placed in pairs, on the dorsal 

 disk, the throat witli a dark streak on the middle of eacli side, the 

 chin yellow, black-dotted. The lateral sternal callosities are large, 

 oblong, and the posterior one round. 



4. Descriptions of Two Species of Crustacea belonging 

 TO the Families Callianassid.e and SauiLLiD^E. By 

 Adam White, Assistant Zool. Dep. Brit. Museum. 



(Plates VI. and VII.) 



The Callianassa here described is from the Camaroons River, W. 

 Africa, whence it was brought by the captain of an African trader to 

 J. Aspinall Turner, Esq., M.P., the well-known possessor of a very 

 fine collection of African insects. Mr. Turner liberally presented it 

 to the Museum, with the information, that this long-bodied Crusta- 

 cean appears periodically in the river in prodigious numbers, which 

 disappear in the course of ten days or a fortnight. The natives are 

 very fond of them, as they are delicious eating ; and as soon as they 

 make their appearance in the river, the men leave their usual pursuits 

 to catch them. 



Genus Callianassa, Leach. 



Callianassa turnerana, n. s. (PI. VI.) 



C. processu rostrali brevifer trispinoso ; digito superiore obtuso, 

 intus quadridentato ; abdominis segmentis tertio quarto quinto- 

 queplagis duabus pellucidis, pilis densis brunneis postice obsitis. 



Long. unc. 6J. 



Hab. Africa occ. (Camaroons). 



Moveable finger of the large claw blunt at the end, the back gra- 

 dually curved, the base with three or four small tubercles arranged 

 longitudinally, and with indications of another row ; the inner edge 

 has four teeth, the two largest near the base, united so as to form one 

 large lobe with another tubercle inside. There is a considerable space 

 left between the moveable finger and the fixed one ; the edge of the 

 latter is toothless, but is hollowed on the inside and at the base, 

 where it is covered with closely placed rounded tubercles ; the im- 

 moveable finger is not much arched, and is pointed. The outside 

 and greater part of the inside of the claw are very smooth, the lower 

 edge being fringed with long and rather coarse hairs, which are ar- 

 ranged in tufts, as they are also, in a double row, on the upper edge 

 of the moveable finger. There are, besides, four rows of distant tufts 



