REPORT ON THE AMPHIPODA. 1553 



Brachyscelus bovallii, n. sp. (PI. CXCVIL, A.). 



This species is closely allied to Brachyscelus rapax (Claus), but smaller and with the 

 head rather more rounded. Claus gives a figure of the animal from the ventral side, 

 showing the long broad groove which separates the eyes on the under side of the head. 

 As this is a very unusual aspect to be figured, because of the difficulty of arranging a 

 specimen suitably for the purpose, it may be mentioned that the specimen from which 

 the new species is described attracted attention by spontaneously assuming the requisite 

 position. Though, however, in this aspect the Challenger specimen closely resembles 

 Claus' species, it is separated from it by various points of detad. 



Upper Antennse. — Peduncle short ; first joint of flagellum long, not strongly curved, 

 the apex little produced, the long convex under side with the usual brush of filaments, 

 the upper margin not very short, carrying a dozen pairs of filaments ; the small second 

 joint twice as long as broad, with filaments at four or five points, the third joint 

 linear. 



Lower Antennse. — Third (first free) joint of peduncle three-quarters the length of the 

 next joint, proximally curved, distally widened, fringed like the following joints with 

 short filaments ; the fourth joint straight, distally widened, the next joint broken and 

 the others missing. 



First Gnathopods. — The lower front corner of the side-plates produced, rounded. 

 The first joint twisted, the elbow behind a little more prominent than the distal 

 convexity of the front margin ; the second joint with two spines at the apex of the hind 

 margin ; the third joint small, very little longer than the second, but distally much wider, 

 with two spines at the hinder apex and one spine on the margin above it ; the wrist 

 of the usual pattern, but with scarcely any pectination, while the teeth are long and 

 slender, five in number above the apical tooth on each margin of the process ; the hand 

 has five teeth on the hind margin, graduated in size, the apical being the longest and 

 reaching nearly halfway along the finger, close to wdiich it lies ; the finger curved, more 

 than half the length of the hand. Claus' figure of the first gnathopod of " Thamyris 

 rapax " shows three teeth on the hand, and on the wrist three teeth on one side and 

 four on the other side of the apical tooth. 



Second Gnathopods. — The first joint almost straight and parallel-sided ; the wrist 

 differing little from that of the first gnathopods, except as usual in not having the 

 prominent rounded apex of the front margin ; the upper part of the hind margin is 

 straight and smooth ; above the apical tooth there are four teeth on the hind margin of 

 the process, and in one limb three, in the other five, on the front, with more serration 

 than in the first gnathopods ; the hand has five teeth on the hind margin besides some 

 serration ; the finger scarcely so long as in the first pair. 



First and Second Perseopod^s very slender, smooth, except for the pectination of 



(zool. CHALL. exp. — part lxvii. — 1888.) Xxx 195 



