1014 THE VOYAGE OF H.M.S. CHALLENGER. 



Hummock Islands, Bass's Straits, in sea-weed on a sandy beach." Dana's Gammarus 

 asper, from the Sulu Archipelago, bears a suspicious resemblance to the present very 

 variable species, but his enlarged drawing of the second gnathopod shows a wrist much 

 too elongated to permit the identification. Mara spinosa, Haswell, is from Tasmania, 

 Gammarus rubro-maculatus, Stimpson, was found " on muddy bottoms in the circum- 

 littoral zone, Port Jackson, Australia," and has been found in the same locality by 

 Mr. Haswell. 



The inner plates of the first and second maxillae differ in armature from those of 

 Maera grossimanus, Montagu, but they differ also from those of Megamcera longimanus 

 (Leach) Bate, in which, moreover, the third joint of the mandibular palp is longer than 

 the second, while here it is shorter, so that I have not ventured to rely on these characters 

 of the mouth-organs for re-establishing Megamcera against the general view that it is 

 synonymous with Msera. 



Mma bruzelii, n. sp. (PL XCVIL). 



Head long in proportion to its depth, rostrum rudimentary, lateral lobes of the head 

 rounded, the lower angle immediately below and a little to the rear of the lobes ; first 

 two segments of the pleon with postero-lateral angles produced in small points, but with 

 the convexity of the hind margin extending beyond these points ; the postero-lateral 

 angles of the third segment sharply outdrawn, and the lower part of the hind margin 

 sharply serrate ; the sixth segment emarginate behind, forming a pair of dorsal teeth 

 separated by nearly the width of the telson. 



Eyes oval, situated near the margin of the lateral lobes of the head. 



Upper Antenrue. — First joint long, rather narrowed distally, grooved on the under 

 side, carrying a few cilia and at the apex below a spine ; second joint longer and much 

 thinner than the first, carrying a few slender setae or setules ; third joint about one 

 quarter the length of the second ; flagellum broken, thirty-five joints remaining in one 

 antenna, thirty-six in the other, of which the first is the longest ; secondary flagellum 

 slender, of nine joints, together as long as the first eleven joints of the primary. 



Lower Antennse broken, evidently much smaller than the upper. First joint not 

 inflated, gland-cone decurrent, not nearly reaching the end of the third joint, which is 

 twice as long as broad, with a small spine in the middle of the upper margin and a 

 group of setae on the lower apex ; the fourth joint slender, rather longer than the first 

 of the upper antennae, with spines at two points of the upper margin near the base, and 

 groups of setae on the lower margin ; the rest missing. 



Upper Lip broadly rounded, the greatest width not far from the front. 



Mandibles. — Cutting plate with one tooth at the upper and two at the lower end of a 

 broad margin ; secondary plate of the left mandible with the broad edge divided into four 



