or THE SOITTHBEN CEOSS EXPEDITION. 



57 



Upper antennae with tlie 1st joint twice as long and half as 

 thick again as the 2nd, which bears the same proportion to the 

 Srd, this reaches to the end of the 2nd joint of the peduncle of 

 the lower antennse. Plagellum very long and slender. Acces- 

 sory appendage one-third the length of the 1st joint of the 

 flagellum, which is transversely striated and as long as the next 

 three joints. 



Lower antennae longer than the upper ; 1st joint less than 

 half as long as the 2nd, which is rather shorter than the 3rd. 



First gnathopods : side-plates rather small, oblong-oval, tlie 

 lower part of the anterior margiu slightly serrate. First joint 

 rather longer than the next three ; carpus rather shorter than 

 the propodos; sides of the propodos almost parallel, the 

 length being to the width as 3"5 to 1'5 ; the hind margins of 

 the 3rd, 4th, and 5th joints are furnished with dense fascicles of 

 setsB, which are plumose and generally forked at the tip. 



Second gnathopods about twice as long as the 1st ; the side- 

 plates like those of the 1st ; 1st joint a little longer than the 

 propodos ; carpus about three-fourths as long as the propodos, 

 the length of which is to the width as 7 to 1*5, both these joints 

 have the hind margins furnished with fascicles of setae. 



First and second perseopods : the 1st joint narrow and about 

 as long as the 5th ; dactylus strong, slightly curved and about 

 one-third as long as the 5th joint. 



Last three pairs of perseopods alike; the 1st joint broadly 

 oval, slightly serrate on the hind margin, and about as long as 

 the 4tli joint ; the 5th joint the longest ; 3rd, 4th, and 5th joints 

 spinous on both margins. 



Uropods subequal in extent ; outer ramus of 1st pair rather 

 more than half as long as the inner ; outer ramus of 2nd pair 

 rather less than half as long as the inner ; outer of 3rd pair 

 more than half as long as the inner, which is wider than the rami 

 of the first two pairs, lanceolate, and finely denticulate on the 

 inner margin. All the uropods are sparsely spinous. 



Telson reaching a little beyond the end of the peduncle of the 

 3rd uropods, concave above. 



Length of female with ova, 9 mm. 



This species affords a good illustration of the unsatisfactory 

 nature of characters taken from modifications of the segmental 

 margins. Along with the specimens as described above were 

 taken a number of others, as a rule smaller, but some very nearly 



