186 IBLA CUMINGII, 



to the surface of attachment, the horns or spines being 

 enveloped in the cement. The prehensile antennae of the 

 larva will presently be described under the male. 



The length of an average specimen, including the pe- 

 duncle and valves, is about half an inch, and the width 

 across the widest part one fifth of an inch. Mr. Cuming 

 has one specimen an inch in length, but this is owing 

 to the peduncle being unusually tapering. In a specimen 

 kept some years in spirits, the cirri, trophi, caudal ap- 

 pendages, and corium under the membrane between the 

 scuta, were all dark purple; the sack and corium of 

 peduncle clouded with purple, and the prosoma pale- 

 coloured. 



The Body (PL IV, fig. 8 d) is small compared with the 

 capitulum and peduncle ; it is much flattened ; the pro- 

 soma is of a very peculiar shape, being square, the sides 

 of equal length, and, in an average-sized specimen, ^th 

 of an inch long. The peculiar shape arises from the 

 great distance between the first and second cirrus — from 

 the mouth being far removed from the adductor scutorum 

 muscle — and lastly, from the lower part of the prosoma 

 being not at all protuberant. The thorax which supports 

 the cirri is also unusually small, plainly articulated, and 

 separated from the prosoma by a deep fold. The thin 

 membrane of the prosoma is studded with some fine, 

 pointed hairs, about ^ths in length, and articulated on 

 little circular discs. 



Mouth, placed at a considerable distance from the 

 adductor, and directed in an unusual manner towards the 

 ventral surface of the thorax : the tropin are arranged, 

 in a curved line, facing the thorax (see PI. V, fig. 2, 

 for this part in the male), and therefore less laterally 

 than is usual. 



Labrum (PI. IV, fig. 8 d opposite c) highly bullate ; 

 the upper part produced into a blunt point : on its crest 

 there are no teeth. 



Palpi (fig. 8 d opposite d) small, blunt and rounded 

 at their ends ; inner margins slightly concave. 



