REPORT ON THE PYCNOGONIDA, 61 
The only specimen of this curious species dredged by the Challenger Expedition is 
a male; the second joints of the two last legs bear on the ventral side distinct rounded 
- tubercles, and at the tips of these knobs the small genital pores are to be observed. 
Habitat— Oorhynchus aucklandie was dredged at Station 169. July 10, 1874, 
Lat. 37° 34’ S., long. 179° 22’ B.. Depth, 700 fathoms. Temperature of the bottom, 
42°C. Sea bottom, grey ooze. 
No other species of Pycnogonid was dredged at this station. 
Observations.—No doubt the genus Oorhynchus is nearly allied to other genera of the 
same group, and especially to the genus Achelia. Although the shape of the body is 
widely different, we find in this genus likewise rudimentary mandibles, ovigerous legs 
furnished with rudimentary denticulated spines and with ‘the four last joints, in general, 
almost of the same shape as those of Oorhynchus. In both genera the genital pores of 
the males are placed on tubercles situated ventrally on the second joints of the two 
posterior legs, They are distinguishable by the shape of the body, which is much 
_ more concentrated and rounded in Achelia, by the number of joints in the palpi, and 
by the absence of auxiliary claws from the legs of Oorhynchus, whereas all the species of 
Achelia, as far as is known at least, are furnished with them. 
Colossendeis, Jarzyusky. 
Colossendeis gigas, n. sp. (Pl. VIII. figs. 1,2; Pl. X. figs. 1-5). 
Diagnosis.—Proboscis bottle-shaped ; cephalic part of the cephalothoracic seoment 
triangular and distinct; eyes obsolete ; third joint of the palpus longer than the fifth, 
palpus as long as the body ; claws of the legs minute. 
Description.— 
No. 1. No, 2. No. 3. No. 4. 
Length of the proboscis, : . : 47°5 mm. 29 mm. 15 mm. 22 mm. 
Length of the trunk (with the abdomen), F 32°'D ,, 20°5,, 1 Des US. 655 
Length of the abdomen, : : : 6 45 3°5,, 2; Dilys 
Length of the palpus, A ; 5 81 3 5S. 55 4 38°5 ,, 
Length of the ovigerous leg, . : E 137 " 90) |; 49 ,, OO 
Length of the leg of the third pair, . : 301 5 PAU 1s 143 ,, 
The body of this gigantic Pycnogonid is robust; nevertheless there are distinct 
intervals between the lateral processes. In the large specimen (No. 1) the surface of the 
body is quite smooth ; the palpi alone are furnished with strong hairs, and the ovigerous 
legs with small ones, while the extremely small hairs on the legs can only be seen with ° 
alens. In the younger specimens the hairs are by no means so scarce. Those on the 
trunk, the proboscis, and the lateral processes are still very small, but the hairs on the 
legs are much more distinct, and, especially at the distal extremities of the joints of the 
legs, rows of short strong hairs may be observed ; finally, the palpi and the ovigerous legs 
