REPORT ON THE CRUSTACEA MACRTJRA. 



153 



subequal to the caxpos, but not so great in diameter ; the dactylos sharp, long and 

 styliform. 



The first pair of pereiopoda exhibits, upon close inspection, the presence of small 

 points or cusps on the inner and outer margins of the propodos, carpos, and meros, in 

 some specimens more abundant than in others, but there are two that, although they 

 vary in proportion, are tolerably constant in position on the outer surface of the meros. 

 There is also one at the outer distal angle of the meros that appears to be constant ; those 

 on the inner and outer distal angles of the carpos are not so constant, more especially that 

 on the outer. There is a strong tooth also at the outer or dactyloid angle of the propodos. 

 It carries a small podobranchial plume attached to a long stalk, 

 that supports a small and delicate mastigobranchial appendage, 

 behind which are two small arthrobranchial plumes. 



The second, third, and fourth pairs of pereiopoda offer no 

 appreciable distinction from those in other forms of this grouj). 

 The gills that each support are the podobranchiae, a small and 

 delicate mastigobranchial lash, two arthrobranchia3, and a pleuro- 

 branchial plume. These increase in proportion as they pro- 

 ceed posteriorly, and those of the fourth pair are large and well 

 developed, but all the rnastigobranchias are of extreme tenuity, 

 except at the stalk, which is fiat and more rigid. 



The fifth pair of pereiopoda is shorter than the others, and 

 terminates in a subequally fringed chela, of which the pollex is 

 rather shorter than the dactylos, and is concave or spoon-shaped. 

 Above this pair, attached to the pleuron on a prominent protuber- 

 ance, is a pleurobranchial appendage that is not equal in proportion to the podobranchia 

 of the preceding pair. 



The branchige may be tabulated as follows : — 



Fig. 36. — Two hairs on a section 

 of chitin, showing their struc- 

 ture. From a drawing by 

 v. Willemoes-Suhm. 



Pleurobranckia?, 

 Arthrobran chias, 

 Podobrancbise, 

 Mastk'obrancbise, 



The first pair of pleopoda is of the form common to the male and female. The 

 others are biramose. 



Observations. — Dr. v. Willemoes-Suhm, in his notes on this species, says, "July 14, 

 1874. ?. Two specimens were taken off Kermadec Island in 500 fathoms; one, the 

 smaller, being 35 mm. in length, and the other 47 mm. The carapace was 22 mm. long 

 and 19 mm. wide. The length of the large chela was 65 mm. but does not equal that of 

 Willemcesia leptodactyla, and is distinguished from it : — 



(ZOOL. CHALL. EXP. PART LII. — 1886.) 



Fff 20 



