242 
HISTORY OF BRITISH CRUSTACEA. 
tubercle at the base. Legs taper, five-jointed, armed with 
a simple nearly straight claw. Tail straight, five-jointed; 
joints equal, distinct, armed on the under side with four 
rows of compressed fins ciliated on the margins, and the 
ultimate joint terminated besides with four similar appen- 
dages and a triangular process between them. 
The large segment is, in some specimens, smooth and 
even, but in others it is raised at the top into two oval 
bosses that greatly resemble the elytra of a Meloe , and are 
beautifully punctured. The same parts are visible on the 
ventral surface in both varieties, but much smaller in that 
whose back is smooth. It may be .a sexual distinction. 
A letter from A. H. Halliday,Esq., dated October 9, 1847,* 
conveyed the following information : “ I found a species of 
Praniza pretty common on the clayey shores of Strangford 
Loch last week, in company with Anceus maxillaris. They 
were in small cavities on the surface of the clay, under stones, 
sometimes singly, oftener two, or even three and four in 
each hole ; the smaller slender green ones were few in com- 
parison. You will find some of the new-born young with 
them, having all the characteristic form of the parent, but 
the posterior thoracic segments not so completely confounded 
* Ann. and Mag. Nat. Hist. n. s. 1848, vol. i. p. 65. 
