SOUTHERN SPHJEEOMLD^E 365 



quite minute. The second antennae are unusually elongate. 

 It is probable that Sregmocerella tricornis, Haswell, from 

 Port Jackson, is specifically as well as generically identi- 

 cal with Ceratoceplialus Grayanus, Woodward, from Bass's 

 Strait, although the figures given differ in some particulars. 



Circeis, Milne-Edwards, 1840. The head and body 

 are comparatively elongate, the segments of the peraeon 

 little flexible ; the first antennae have a very large basal 

 joint, with the second joint embedded in its apical emargi- 

 nation; the uropods have the outer branch longer than the 

 inner. Both the species are southern, and their names 

 tridentata and bidentata refer to the apical notching of the 

 pleon. 



Amplioroidea, Milne-Edwards, 1840, has the first joint 

 of the first antennas greatly dilated ; the first segment of 

 the pleon distinct but rudimentary ; both the branches of 

 the fourth and fifth pairs of pleopods transversely fluted for 

 branchial purposes. The type-species, Amplwroidea typa, 

 from Chili, seen from above and by help of the projecting 

 first joints of the upper antennas, has the outline of a jar 

 or amphora. Dana names a second species cmstraliensis. 

 G. M. Thomson describes Amplwroidea falcifer, from New 

 Zealand, but thinks it may be identical with one or other 

 of the two species just mentioned. 



Cassidina, Milne-Edwards, 1840, has the body greatly 

 dilated beyond the insertions of the slender legs. The 

 uropods do not reach the narrow apex of the terminal 

 segment, and have the outer movable branch much smaller 

 than the fixed inner one. Cassidina typa, Milne-Edwards, 

 is only a third of an inch long. The species latistylis, 

 Dana, is said by Miers to be a synonym of emarginata, 

 Guerin-Meneville. This, according to Stucler, reaches a 

 length of an inch and a quarter and a breadth of more 

 than four-fifths of an inch in the male, though the female, 

 which is a little over an inch in length, is only two-fifths 

 of an inch broad. Studer describes a third species, Cassidina 

 maculata, which, like emarginata, is found at Kerguelen 

 Island, and G. M. Thomson describes a fourth species, 

 Cassidina neo-zealanica, from New Zealand. 



