154 



Tlie second, third, and fourth segments of the pereion are all 

 about equal in length, being about three times as long as the first 

 in the centre. They are of the same length throughout from side 

 to side. The inferior margins ate slightly concave in the centre 

 for the reception of the batii of the legs (epimer-a) and have the 

 anterior angle slightly produced and tipped with setie while the 

 posterior angle is regularly rounded. (See Plate xxiii., lig. 1, and 

 also Plate xxv., fig. 4). 



The tifth, sixth and seventh segments are similar to one another, 

 the fifth being somewhat shorter than the fourth, and the 

 sixth and seventh each shorter than the preceding segment. The 

 epimera extend along almost the whole of the inferior mai'gins 

 and tit into rather deep triangular- eniarginations ; both the 

 anterior and posterior angles of the margins are tipped with setie 

 (see Plate xxv., tig. .5). . 



Epimera. — The first to fourth epimera inclusive are all sinular 

 in form, and consist of two lobes separated by a distinct cleft 

 reaching upwards from the inferior margin more than half way 

 to the upper margin. The epimeron of the first segment is rather 

 deeper than those of the other three, in the first and second the 

 two lobes of the e^oimera are of about equal size, iu the third and 

 fourth the anterior lobe is lai'ger than the posterior. The margins 

 of the epimera are free from setie. (Plate xxv., fig. 4.) 



The epimeia of the fifth, sixth, and seventh segments are all 

 similar and are triangular in shape fitting into a triangular emar- 

 gination in the inferior margins of the segments. The posterior 

 angle is produced a little and is tipped with three or four setaj, 

 while the anterior angle is somewhat rounded and bears no sette. 

 There are usually two or three short seta^ on the surface of the 

 epimera. (Plate xxv., fig. 5.) 



Pleon. — The first segment of the pleon is nearly as long as the 

 seventh segment of the pereion in the centime of the dorsal surface, 

 but gradually narrows somewhat inferiorly. It extends downwards 

 slightly beyond the epimeron of the seventh segment of pereion and 

 has the lower margin regularly rounded. The second, third, fourth, 

 and fifth segments are similar, slightly longer dorsally and not 

 narrowing inferiorly and they are produced downwards consider- 

 ably further than the first segment. The sides of the segments 

 (pleura) are thus fully as well developed as in any of the Araphi- 

 poda, and form, as in the Amphipoda, a latei'al protection for the 

 pleopoda. The body part proper in the fifth segment is separated 

 from the pleuron by a slight depression. The sixth segment and 

 the telson appear completely coalesced, forming a tail piece regu- 

 larly convex above, curving posterioi-ly as well as from side to 

 side ; posteriorly it ends in a small narrow projection tipped with 

 stiir set;e. From the upper corner of the articulation of the 

 uropoda with the segment a short ridge bordered with seta^ ex- 



