APPENDIX. No. IV. 413 



Pentalasmis.* 



Divisions of the genus. 

 * Hhider scale simply arcuated. Lateral scales smooth. 

 ** Hinder scale simply arcuated. Lateral scales costated. 

 *** Hinder scale abruptly bent below the middle. 

 Sp. 1 . Pentalasmis (*) Chclonia. Superior scales broad, rounded at their points, 



hinder scale convex. Found on turtles in N. lat. 36, 15, W. long. 



16, .S2, 0. Page 9. 

 Sp. 2. Pentalasmis (*) Hillii. Superior scales narrow, anteriorly obliquely-trun- 

 cated ; (hence as if produced behind), hinder scale carinated below. 

 Sp. 3. Pentalasmis (**) Spirula\ Ratln^r convex, upper scales Tvith their points 



anteriorly produced. 

 /3 Witli the ribs spined. Fo\ind in great abundance adhering to the floating 



shells of Spirul.e. (to which in several specimens part of the animal still 



adhered) 2, 0, (» N. lat. 10, 17, W. long. 

 Sp. 4. Pentalasmis (**) dilatata. Larger scales anteriorly dilated, hinder scale 



with granulated striae (often behind with two or four teeth.) 0, 14, 0, N. 



lat. 6, 18, r>.', E. long, adhering to Janthina J'ragilis. 

 Sp. 5. Pentalasmis (***) Donovani. Hinder scale, with a longitudinal elevated 



little line ; angle rectangular ; bend obtuse with a transverse elevated little 



line. Taken in 0, <8, S. lat. 7, .50, E. long 

 Sp. 6. Pentalasmis (•**) Spirulicola. Hinder scale naiTOw carinated from the 



apex to the angle ; angle rectangular, geniculated, prominent. Found on 



shells of Spirula, 22, 0, N. lat. 1 !», 17, W. long. 



Crustacea. 



Portunus, (a new species,) without spines on the front aspect of its arms, was 



taken in the Gulph of Guinea. 

 Lupa ; of this genus three new species were discovered, aU of which belong to 



that section in which the hinder lateral spine of the shell is very much 



elongated. 

 Machcerus ; a new genus allied to Gonoplax, but differing in having short 



* The peduncle of those of the first division is very long, or moderately so ; of the 

 two other divisions extremely short. 



