72 



THE VOYAGE OF H.M.S. CHALLENGER. 



Colossendeis hrevipes, n. sp. (PI. X. figs. 8, 9). 



Diagnosis. — Lateral processes not very widely separated. Palpus less than once and 

 a half as long as the proboscis, with the three last joints bent over like a hook. Ovigerous 

 legs with the denticulate spines of the four last joints numerous and comparatively short. 

 Length of the legs unequal, short. Otherwise this species resembles Colossendeis gracilis, 

 Hoek. 



Description. — 



Length of the proboscis, 

 Length of the trunk. 

 Length of the abdomen. 

 Total length of tlie body. 

 Length of the palpus, 

 Length of the ovigerous leg, 

 Length of the leg of tlie first pair. 

 Length of the leg of the second pair, 

 Length of the leg of the tliird pair. 

 Length of the leg of the fourth pair, 



This true deep-sea species is also nearly allied to Colossendeis gracilis. The first time I 

 examined it I was struck with the shortness of the legs, especially in the largest specimen ; 

 but as it is possible that this length varies greatly imder diff"erent circumstances — as it 

 certainly does with age— it is necessary to use the utmost care in judging of this charac- 

 teristic mark. The body, proboscis, trunk, and abdomen are as in Colossendeis gracilis, 

 the only difference being that the lateral processes are not quite so widely separated. 



The palpus is short, only one-fourth as long as the proboscis. The last tliree joints 

 are extremely short, shorter than the seventh joint ; they are bent like a hook, the tenth 

 joint hanging down parallel with the seventh joint (fig. 8). 



The ovigerous legs are comparatively long, 29 mm. in a specimen of 19 mm. The 

 last four joints are small and furnished with a rudimentary claw, the length of which is 

 nearly one-fifth the length of the tenth joint. A drawing of the denticulate spines on 

 one of the four last joints of the ovigerous leg is given in fig. 9. The spines are short 

 and flat and do not show small hairs at the periphery. There are two regular rows, the 

 outermost of which has the stoutest and longest spines, whereas the irregularly placed 

 spines on the other side decrease in size. The length of the legs is very unequal. The 

 specimen with the shortest legs is a full-grown female. The claw at the end of the 

 eighth joint is very long, longer than that joint. The Ijody and legs are almost entirely 

 smooth ; there are small hairs on the last joints of the palpi. 



The genital pores of both specimens, the largest of which is a female, are found 

 ventrally on the second joint of all the legs. 



Habitat. — This species was dredged from the greatest depth at which a Pycnogonid 

 has been found, viz., 2650 fathoms. 



