SUPPLEMENT 195 



separated from the hinder part of the head by a second transverse ridge which extends between the 

 anterior limit of the eyes. The hinder part of the head, between the eyes, is raised into two low, 

 rounded prominences and between these, in the posterior median position, is a very small rounded 

 projection. The region between the sutures separating the head from the second thoracic somite is 

 marked by a shallow groove. The eyes are reniform in shape and contain black pigment. 



As in all the members of the Serolidae, the second thoracic (first pereion) somite is fused with the 

 head, the limits of which may be seen laterally by the presence of sutures. The median portion of the 

 tergum of this and the succeeding somites, both thoracic and abdominal, is raised in a slight keel. 

 The coxal plates of all the segments are somewhat thickened at their lateral margins ; in this character 

 the species resembles S. bouvieri Richardson (1906, pp. 7-10), where a similar but much greater 

 thickening occurs. The third, fourth and fifth thoracic (second-fourth pereion) somites are subequal 

 and their terga are separated from their respective coxal plates by sutures ; the terga of the sixth and 

 seventh thoracic somites together have a length less than one of the preceding ones ; that of the seventh 

 is about half the length of the sixth; the tergum and coxal plates of the last thoracic somite, as in most 

 species of Serolis, are absent. 



The terga of the three free abdominal segments are subequal and each is equal to the combined 

 length of the sixth and seventh thoracic somites; the pleural plates of the second and third segments 

 extend back beyond the coxal plates of the seventh thoracic somite, those of the third are shghtly 

 longer than the second, and reach to the level of the distal extremity of the protopodite of the uropods. 

 The terminal segment is broader than long, somewhat pentagonal in outline, with thickened margins 

 and a raised central area, the latter forming a broad keel, which narrows towards the posterior 

 extremity of the segment and disappears a little distance from the tip of the segment, which is rounded 

 and slightly keeled; arising from the broader portion of the keel, on either side, is a series of three 

 delicate ridges (Text-fig. 27) w4iich curve outwards and backwards and disappear some distance from 

 the margins of the segment. 



The peduncle of the antennule (Text-fig. 28 a) consists of four joints, the first one of which is broad 

 and geniculate, with a raised, rounded longitudinal ridge extending from the middle of its distal upper 

 margin to a point a little short of the geniculation ; a similar ridge is present on the second joint which 

 is broadest at its distal end and is about two-thirds the length of the first; the third joint is a little 

 longer but about half the width of the second, and the fourth is a third of the length of the third: 

 the flagellum consists of seventeen joints, the distal one of which is very small; a single sensory seta is 

 present at the distal end of each joint except the first four. 



The antenna is shown in Text-fig. 286; the first joint of the peduncle is short; the second and third 

 are subequal, but the second is broader than the third which is narrower at its proximal end; the fourth 

 and fifth are subequal and three times as long as the third; the fifth is narrower than the fourth; 

 these two last-mentioned joints each possess five groups of delicate hairs which are found on raised 

 areas along their anterior margins; a longitudinal ridge is present on all except the first joint of the 

 peduncle; the flagellum is shorter and narrower than the fifth joint of the peduncle and consists of 

 eleven joints, the distal one of which is small. 



The moiithparts are of the usual type, the form of the maxillula, maxilla and maxilliped may be seen 

 in the Text-fig. 270, b and c. 



The first, second, sixth and seventh pereiopods are shown in Text-fig. 28c, d, e and/. The first 

 pereiopod, as usual, is of a stout build, with the propodus greatly expanded and with its inner margin 

 armed with a row of about thirty-three broadly oval processes alternating with modified spines similar 

 to those illustrated for S. acuminata (Text-fig. 25/). The distal edge of the carpus is crenulate and 

 bears two spines similar to those on the propodus. 



