126 THE VOYAGE OF H.M.S. CHALLENGER. 



straight for the first half, the margin being fringed with fine, closely-set denticles; the 

 distal half is furnished with blunt tooth-like processes, and is bent downwards at an 

 oblique angle ; it terminates in a short pointed extremity which is bent upwards ; 

 towards the distal extremity are a few slender hairs scattered here and there ; the 

 finger gradually narrows towards its termination in a curved pointed extremity ; the 

 inner margin is provided with a number of low tooth-like processes, each terminating 

 in a sharp point which is directed forwards. 



The remaining thoracic limbs are more or less similar to each other; there is no 

 difference in size between the anterior and posterior series, but a slight difference in 

 structure ; the proximal joint is very long, the second extremely short ; the third is 

 about half the length of the proximal joint, the fourth and fifth are rather shorter and 

 subequal ; the terminal joint of the limb has the form of a long slender spine ; rlie inner 

 margin of the penultimate joint has a row of stout spines, of which the distal one or two 

 are serrate, on the opposite side of the joint are a number of more slender, hair-like 

 spines ; the antipenultimate joint has a similar structure, but the spines are not so 

 strong; the distal joints are nearly smooth, having only a very few slender hairs 

 developed at the point of articulation with the succeeding joints. The above description 

 applies to the first three pairs of ambulatory limbs. The fourth, fifth, and sixth pairs 

 of thoracic appendages differ slightly in their structure from the anterior pairs ; 

 this difference mainly concerns the terminal joint of the limb, which is considerably 

 more elongated than in the anterior appendages ; it terminates in a fringe of short 

 spines and mesially in a long slender spine which is of about half the length of the 

 joint. 



On the abdomen all the appendages are present, but they present no special features 

 of interest, with the exception of the uropoda, which have a typical structure. 



The basal joint of the uropoda is very stout and long, and with it articulates the 

 minute two-jointed exopodite, as well as the long slender endopodite which is made up of 

 eight separate joints, all of which have tufts of hairs near to their articulation with the 

 succeeding joints. Both the endopodite and the exopodite end in a tuft of slender hairs ; 

 the length of the uropoda is nearly equal to that of the abdomen. 



Another example of this species was dredged in the North Atlantic from a depth of 

 1250 fathoms; it presents certain slight differences from the above described species; 

 these differences have reference to the proportionate length of the thoracic segment s ; seeing, 

 however, that the two specimens come from widely distant localities, it appears t<> be 

 unnecessary to found a specific distinction between the two individuals, at least for the 

 present. The present specimen is stouter and more robust than the last, but of equal 

 length; the cephalothorax is nearly as long as the first three segments of the thorax 

 taken together, the thoracic segments gradually increase in length up to the fourth ; the 

 fifth and sixth segments are subequal and about as long as the third. 



