58 



TERRA NOVA" EXPEDITION. 



Proboscis about two-thirds of length of trunk, widest about the middle, where its 

 width is less than half its length. 



Abdomen horizontal, little shorter than proboscis, reaching beyond middle of 

 second coxa of last legs, slightly clavate and bluntly pointed. 



Chelophores extending to, or a little beyond, middle of proboscis. Palps with 

 second and fourth segments equal, sixth and seventh produced ventrally, terminal 

 segment little longer than preceding. 



First coxce each with two conical tubercles of which the posterior is the larger. 

 Femur and first and second tibise subequal or slightly longer successively ; femur from 

 about three times as long as deep in the female to more than six times in the male. 

 Auxiliary claws one-third as long as main claw. 



Sexual differences. — Apart from the usual differences in the diameter of the 

 femora, the males apparently tend to have the trunk more elongated and the lateral 

 processes more widely separated than in the females ; they have also the tubercles 

 on the lateral processes more prominent and those of the first coxse forming spurs 

 which may be as long as the width of the segment. 



Variation. — The specimens examined differ among themselves in the relative 

 length of the body, the degree of separation of the lateral processes, and the 

 length of the legs. Two extreme types are represented in Figs. 13 and 14, but 

 many specimens are intermediate. In the more elongated forms the spiniform tubercles 

 on the lateral processes and first coxae are longer, as is also the conical apex of the 

 ocular tubercle. 



Two specimens differ from the typical form in the segmentation of the body. In 

 one, there is a very distinct articulation between the last two somites ; in the other, 

 the only articulation is between the first two. 



Measurements, in mm. — The measurements here given are taken from two fairly 

 representative specimens : — 



Length of proboscis 



Greatest width of proboscis . 



Length of trunk 



Width across second lateral processes 



Length of abdomen 



Third right leg — 



Coxse ..... 



Femur . . . . 



First tibia .... 



Second tibia .... 



Tarsus and propodus 



Main claw .... 



Auxiliaries .... 



