74 THE VOYAGE OF H.M.S. CHALLENGEE. 



joints. In the posterior antennse (fig. 10) the filament has ten joints ; the two last 

 joints of the basal portion of the antenna are furnished with tufts of fine hairs springing 

 from shallow depressions on the anterior surface. 



The ambulatory limbs are remarkable in that they are only furnished with com- 

 paratively slender, soft, bluntly terminating spines; no serrated spines appear to be 

 present. The inner side of the first joint of all these appendages has a row of about a 

 dozen fine branched hairs entirely like those found in many other species ; the second 

 joint in. all is rather smaller than the first, and has on the inner side just before its 

 termination a single long slender spine ; the remaining joints are subequal in size and 

 comparatively short ; the fourth and fifth joints in the penultimate pair of appendages 

 are longer and narro^\^er than in the preceding limb, and about half as long again as the 

 third joint. 



The last pair of thoracic appendages is as usual small. 



The three first abdominal a])pendac)es have the basal portion comparatively long 

 and narrow, and as in other Australian species the inner and lower margins are not 

 prolonged into a triangular process furnished with two or three branched hairs. 



l!.\x& fourth pair or opercida have the exopodite divided by a suture at right angles to 

 the longitudinal axis, and terminating exactly at the level of the attachment of the 

 uropoda ; the latter are attached at about the middle of the caudal shield, and extend 

 exactly as far as its termination; the endopodite is slightly shorter, and at the same time 

 slightly broader than the exopodite ; the margins of both are smooth, and only slightly 

 crenate at the distal end ; they bear no branched hairs. 



Station 161, April 1, 1874; lat. 38° 22' 30" S., long. 144° 3G' 30" V/. ; 33 fathoms; 

 bottom, sand. 



15. Serolis pallida, F. E. B.(Pls. VII. fig. 1 ; VIII. figs. 6-16). 



Senilis jKillida, F. E. Bed Jar J, Proc. Zool. Soc. Lond., 1881, jit. iii. p. 335. 



Of this species two specimens were obtained, a male and a female. The female is the 

 larger, measuring 16 mm. in length and 13 mm. in breadth; the male measures 9 mm. 

 in length and 7 mm. in breadth. 



The body is oval, somewhat pear-shaped, and recalls Serolis convcxa ; as in that 

 species the epimera are closely applied to eacli other, and only in the last three thoracic 

 epimera are the extremities freely projecting. The colour (in alcohol) is a uniform pale 

 brown, with t\A'o darker patches on each side of the third free thoracic segment, the 

 anterior portion of the caudal shield is whitish grey. The surface of the body is quite 

 smooth and free from tubercles except for a series, one to each segment, occupying the 

 median line. 



