Kcv. T. 11. 11. Slcbbing on Crustacea. 19 



curved, acute at the base, tlie rounded apex closely ap- 

 proacliin<T the excavated m:ir<i:in of the tergum ; the l)isal 

 scu:iiiout shorter than the occludent, but very nmch wider, 

 trian_i,ailar, the longest sitle slightly convex, lying very near 

 to the inner margin ot' the occludent segment ; the lower side 

 overlap])ing the basal part ot" the carina; the inner side 

 slightly convex at the centre. The junction of the two seg- 

 ments is not solidly calcified. 



Ter<]a. — The Uj)per ])art projecting with an obtuse or acute 

 apex towards the occludent margin of the capitulum, the valve 

 widening downwards, so that the outer margin is deeply 

 excavate, while the inner or carinal margin is nearly straight. 



Carina. — Strongly bowed, overlapping the terga for more 

 than half their length ; the basal part at right angles to the 

 remainder, and externally concave, so that it is not possible 

 to see the two ))arts of the valve dorsally in one view ; the 

 distal border of the base is not emarginate. 



Mandibles. — There are five teeth, that at the extremity of 

 the convex margin the largest and remote from the others, 

 the furthest from it of the remaining four being compara- 

 tively broad and denticulate. 



First Ma.vilhv. — The notch which follows the principal 

 spines is shallow. 



Cirri. — The first and shortest pair are not very remote 

 from the second ; the rami have six or seven joints of no great 

 length, carrying numerous spines; the rami of the other pairs 

 have from eight to ten joints apiece, the sixth pair having the 

 smaller number. The setose s[)ines are not numerous. 



The one-jointed caudal appendages are short and narrow, 

 tipped with a group of seta-like spines of various lengths, and 

 carrying one or two of no great size below the apex. The 

 ]icnis has a group of spines or set£e on the narrow blunt apex, 

 and some setulcs are scattered over the surface, which in the 

 two specimens dissected was greatly widened at the middle. 



Hize. — The specimen represented in fig. B is a little over 

 three twentieths of an inch, the peduncle being rather more 

 than one twentieth and the capitulum rather more than two 

 twentieths, the parts to some extent overlapping one another. 



The species is named in compliment to Dr. P. P. C. Hoek. 

 The s[)ecimens were sent me by my obliging correspondent, 

 \V. K. Forrest, Esq., trom Antigua, where he found them on 

 the mouth-organs of a Palinurid. 



Dichelaspis antiffuw, sp. n. (PI. II. figs. E-G.) 

 At the first glance I supposed this species to be merely a 

 variety of the preceding; but upon dissecting a specimen and 



2* 



