26 THE VOYAGE OF H.M.S. CHALLENGED. 



The first pair of thoracic appendages are modified into a prehensile hand; they are 

 stouter and shorter than the succeeding appendages of the thorax ; the first joint of the limb 

 is rather short and slender, the following joint is of equal length but much stouter; the 

 third joint is much shorter and narrower ; in every case these joints arc wider at the 

 articulation with the following joints than with the previous; the fourth joint of the 

 limb is extremely large and stout and triangular in form ; the distal side forms a cutting 

 margin against which the comparatively small fifth joint plays. 



The remaining thoracic appendages are more slender than the first pair but still stout, 

 and their great length is characteristic of the genus ; the more posterior pairs of these 

 appendages are considerably longer than the body; the three basal joints are compara- 

 tively short and subequal; the fourth joint is long and equally stout, and provided with 

 tufts of spines ; the fifth joint is the longest but considerably more slender than the pre- 

 ceding; it is also furnished with tufts of hairs and spines; the sixth joint is very 

 stout and the limb ends in two claws. 



The uropoda are small conical stumps placed near to the end of the abdominal shield. 



Station 149d, off Royal Sound, Kerguelen, January 20, 1874 ; lat. 49° 28' S., long. 

 70° 13' E. ; depth, 28 fathoms; volcanic mud, 



Munna pallida, F. E. Beddard (PL XL fig. 15). 



Munna pallida, F. E. Beddard, Proe. Zool. Soc. LonJ., 188G, pt. i. p. 98. 



The present species is also from Kerguelen, and Like the last is represented by a single 

 male individual ; this species, however, has the more typical characters of a male in being 

 elongated and of approximately equal breadth throughout. 



It affords a transition to such genera as Jsera by the structure of the eyes, which are 

 small and not raised upon stalks as in the typical Munna ; the free abdominal segment, 

 the elongated thoracic appendages with two terminal claws, and the rudimentary conical 

 uropoda show that this species in other respects conforms to the same generic type as the 

 last. 



Munna pallida is a smaller species than the last, measuring rather less than 

 3 mm. ; it is pale and transparent and without the black pigment spots of Munna 

 maculata. 



The head terminates in a straight truncated anterior margin, the lateral notches for 

 the reception of the antennules are deep, the lateral regions of the head arc pointed 

 anteriorly and rounded posteriorly; the eyes are conspicuous and placed just behind the 

 antennules ; they are quite sessile, not raised on a stalk as is so usual in this melius. 



The first segment of the thorax is longer than any of the three succeeding, which are 

 subequal ; the lateral margins of these segments are rounded ; the epimera which are 

 small are also rounded laterally. The three posterior segments of the thorax gradually 



