PYCNOGONIDA. 59 



COLOSSENDEIS AUSTRALIS. 



(Plate IX., fig. 1 ; Plate X., figs. 1 and 2.) 



Specific characters : 



Body stoufc, with lateral processes widely separated, minutely scabrous, the spines being arranged 

 in distinct rows on the appendages. 



Proboscis enormous, bottle-shaped, more than half as long again as the body. Eyes, four, well 

 developed. 



Palp 10-jointed, the eighth and ninth joints equal, the tenth longer. 



Claw of legs less than half the length of the propodus. 



Under a lens the entire animal exhibits a beautifully mottled appearance, which, 

 to a greater or less extent, appears to be characteristic of the genus. The Body 

 shows the faintest traces of segmentation ; the cephalon is short and only very little 

 expanded, and the first pair of lateral processes is placed close against it. 



The Ocular tubercle is situated in the middle of this area and is stout, with four 

 well-developed eyes, two anterior and two posterior, the latter smaller than the others. 



The Proboscis is of much greater diameter than the body, to which it is movably 

 articulated ; throughout the greater part of its length it is curved downwards ; the 

 mouth is very large. The organ is covered with minute spines, which seem to have, to 

 some extent at least, an indistinct linear arrangement ; the difficulty of making out 

 their precise arrangement is accentuated by a growth of polyzoa. 



The Abdomen is of moderate dimensions and somewhat clavate. 



The ten-jointed Palp arises ventro-laterally, as close as possible to the proboscis. 

 The two first joints are very short, and the third is rather more than twice the length 

 of the fifth ; the fourth is small ; the sixth is barely one-third the length of the fifth, 

 and the seventh is about half as long again as its predecessor ; the eighth and ninth 

 are shorter and sub-equal ; the terminal one is absent from one side and injured on the 

 other, but in the other specimen available it is a little longer. The lateral line appears 

 along the greater part of the appendage. The entire limb is spinose, beginning with 

 the third joint, and the minute spines are arranged longitudinally in rows as far as the 

 end of the fifth joint, which, with the two preceding, bears a more or less complete 

 whorl of spines at its distal extremity. Beyond the fifth joint the spines become stiff 

 setse rather than spines; they are larger and more abundant and irregular, besides 

 being aggregated on the ventral and inner side in the natural position of the limb. 



The Ovigers are very long and, as characteristic of the genus, 10-jointed (fig. la). 

 They arise from a small body-process immediately behind the palps, but nearer the 

 middle line. The first three joints are small, the fourth and sixth are the longest and 

 sub-equal, the fifth being about a quarter their size. The last four are sub-equal, and 

 the appendage terminates in a small claw. The lateral line is distinctly marked. The 

 entire limb is spinous. A few minute spines exist on the first three joints, beyond 

 these they are arranged more or less clearly in lines and are more numerous. Then- 

 is also a fringe of small spines on the outer margin of the distal extremity of each 



