158 Proceedings of the Royal Society of Victoria. 



First Uropoda (Fig. 1). — The first uropoda extend beyond the 

 extremity of the second uropoda. The peduncle is twice the 

 length of the rami, and bears three spines on the dorsal surface, 

 two being situated on the outer margin, and one distally on the 

 inner margin. The rami are similar to each other, each curving 

 very sliglitly upwards, with bluntly rounded ends, bearing three 

 short spinules and one long one, all of which point directly 

 upwards ; along the upper margin of each there are also two 

 short spinules. 



Second Uropoda. — The second uropoda are only half the length 

 of the first uropoda, but are subequal in form. 



Third Uropoda. — The third uropoda are remarkably long, 

 equalling in length that of the entire pleon. They are carried 

 normally in a vertical position, and doubtless possess a special 

 sensory function, for I have determined thereon, what are 

 evidently from their structure, sensory hairs (Fig. 13). They 

 are very similar in appearance under high magnification to 

 those I noted on the first antennas of Phreatoicoides gracilis, and 

 described under " C " form.^ The peduncle is very short and 

 robust, the anterior margin concave, and the hinder margin 

 evenly convex, with a tuft of six or more stiff setpe on its distal 

 extremity which point upwards and landwards. There is only 

 one ramus, and no appearance of a second one remaining. This 

 single ramus is two-jointed, the proximal one being slightly the 

 longest as well as also being the stoutest ; the hinder margin is 

 straight ; the posterior margin also is straight, but narrows l)oth 

 at its proximal and distal attachments. On the distal margin 

 there is a circlet of sensory sette similar in appearance to Fig. 13, 

 and in two places equi-distaut from the proximal and distal ends 

 there are, on the hinder margin, two spinules pointing hind wards, 

 and near to each of these, on the outer surface, there are two or 

 three spinules pointing hindwards, and also in addition there are 

 two or three fine setae on the hinder margin near to the attach- 

 ment with the peduncle. The second joint has the margins 

 nearly straight, and extremity bluntly pointed, from which 

 springs a circlet of long fine sensory setae similar to Fig. 13. 

 The hinder margin has two spinules disposed as in the first 



1 Aiitea, p. 128. 



