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



segments broad and well developed in the female ; five pairs of appendages present. 

 Special features of the male unknown. 



Latreillopsis occupies an intermediate position between the genera Homola and 

 Latreillia. From Homola it is distinguished by the arrangement of the rostrum and 

 supraorbital spines, the greater length of the ocular peduncles, and more especially 

 by the elongated cylindrical legs. In Latreillia, on the other hand, the frontal region 

 is narrow and produced so as to give the carapace a triangular outline, the supraorbital 

 spines are more strongly developed, and the eye-stalks and legs are of greater length. 



It is to be noted that Station 209, at which the single specimen of Latreillopsis 

 occurred, is one of the two localities in which species of Homola and Latreillia were taken 

 by the ChaUeuger. 



Latreillopsis hispinosa, n. sp. (PI. II. fig. 3). 



CJiaracters. — Carapace somewhat rectangular, the length greater than the breadth, 

 the surface irregular. Frontal region with three long acute spines, of these the median 

 or rostrum is directed forwards and is about half the length of the other two, which are 

 supraorbital in position, and placed as regards the rostrum at an angle of about 45". 

 Gastric region swollen, armed posteriorly with a rounded tubercle and a transverse row 

 of slight elevations in front of this. Cardiac and branchial areas not sharply distinct 

 from one another, their surfaces with numerous irregularities. The pterygostomial area 

 partly appears on the dorsal surface, and gives rise to a well-defined elevation about tin- 

 middle of the lateral border ; anteriorly it is separated from the hepatic and subhepatic 

 regions by a deep groove. The hepatic and subhepatic areas .are apparently fused 

 to form an oblique oval elevation capped by two acute anteriorly directed spines 

 (hence the specific name), the superior of which is equal in size to the rostrum, the 

 inferior slightly shorter ; this region is separated from the margin of the buccal cavity 

 by a narrow groove. The epistome is somewhat triangular, and the buccal margin 

 remarkably pronounced, with two subacute lobes near the upper angle on each side. 



The eyes are of moderate size, and the corneae dilated ; the basal segment of the 

 peduncle is long and cylindrical. The antennules have their basal segment dilated, and 

 the second and thii'd joints cylindrical; the fiagella are of small size. Situated between the 

 basal joints of the antennules, and on that portion of the epistome which passes towards the 

 frontal region, is a small unpaired tubercle. The antennal peduncle is apparently composed 

 of four segments : the first is of small size and bears a rounded tubercle on its inner surface 

 (it is also overhung by a small acute spine which rises from the frontal margin) ; the 

 second joint is stouter than, and about half the length of, the third, it bears a short 

 prolongation at its inner border and distal end ; the third and fourth segments are 

 slender and cylindrical, the ultimate about one-third the length of the penultimate ; the 



