178 Transactions. — Zoology. 



is a rudimentary secondary appendage only about half as long as the 

 first joint of the flagellum. Peduncle of lower antenna equal in length to 

 that of the upper, the last two joints equal in length. Appendage of the 

 mandible three-jointed, the second joint larger than the first, the third short 

 and curved. Second gnathopoda more slender than the first. Last three 

 pairs of pereiopoda increasing in size from before backwards, the various 

 joints being pretty abundantly supplied with stout setae. Last three pairs 

 of pleopoda slender, biramous, the penultimate the smallest and having 

 the rami slightly unequal, the rami in the other two being equal. Telson 

 short, as long as broad, the posterior border slightly concave. 



Male. — Differs in having sensory capsules and setsB on both pairs of 

 antennae, and in having the gnathopoda much larger than those of the 

 female. First pair of gnathopoda much larger than the second, propodos 

 very large ; palm broad, defined by one long and two short spines, the long 

 one being about two-thirds the length of the finger. Second pair much 

 smaller, palm defined by a short, stout spine. Colour — transparent. 



Length of female (with eggs), -3 inch. Male (largest specimen), -5 inch. 

 Hab. Pump at Eyreton. 



This species differs from the other species of CaUio2)e in the absence of 

 eyes and in the presence of a rudimentary secondary appendage on the 

 upper antenna, but I have not considered this sufficient to warrant its 

 removal from the genus. The female is very abundant, but the male is 

 rarely obtained. 



The number of joints in the flagella of the two antennae varies very 

 much (in the female) according to the size and therefore presumably 

 according to the age of the animal. Thus in very small specimens I found 

 15 joints in the flagellum of the upper antenna and 7 in the lower, while 

 in full-sized specimens there were about 55 in the upper and 21 in the 

 lower. 



In the male, peculiar " sensory capsules " are found on both antennae. 

 They are to be found on the last two joints of the peduncle and on the 

 proximal half of the flagellum of the upper antenna ; on the distal half 

 simple sensory setae (fig. 4 b) are found on every other joint. The sensory 

 capsules are also present on all the joints of the flagellum of the lower 

 antenna except the last two or three. They are cup-shaped and slightly 

 constricted towards the middle, and they are situated on a slight protuber- 

 ance of the joint of the flagellum (fig. 4 a). On the peduncle of the upper 

 antenna of the male there are other peculiar-looking setae which are 

 evidently sensory. They are long and slender, with several very fine 

 divergent filaments at the distal end (fig. 3). Similar capsules and setes 



