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X. On some new Exotic AmpMpoda from Singapore and New Zealand. 

 By the Mev. Thomas E. E. Stebbing, M.A. 



Eeceived November 12th, 1885, read January 19th, 1886. 



[Plates XXXVIII., XXXIX.] 



IN the collections made by Brigade-Surgeon S. Ai-cher, to illustrate the 'Marine Fauna 

 of Singapore,' numerous Decapods are included, a few Isopods, and one Amphipod 

 specimen. This last has been passed on to me for description by my friend Mr. Alfred 

 O. Walker. Although it does not exactly correspond with Boeck's description of 

 Byhlis, inasmuch as the last uropods are not very short, and the telson is deeply bifid, 

 in other points it so well agrees with it that I should be unwilling to add to the sub- 

 division of the Ampeliscaidse, ahready perhaps carried unnecessarily far. 



The two species from New Zealand were sent me by my friend Mr. G. M. Thomson, 

 a well-known carcinologist, with brief preliminary descriptions, and the names respec- 

 tively Talorchestia tumida and Pherusa (^) cmrulea. No females of the Talorchestia 

 were sent me. The Pherusa seems to fit in more accurately with Boeck's closely allied 

 genus Amphithopsis, and may therefore be introduced to the world as Amphithopsis 

 coerulea, Thomson. [See, however, the P.S. p. 208.] 



I. Byblis kallaethrus, n. sp. (Plate XXXVIII.) 



The four round simple eyes have the shining yellow plate in each surrounded by a 

 mass of dark pigment. 



The upper antennae not reaching to the end of the peduncle of the lower ; the first 

 joint short, inflated ; the second between two and three times as long, slender ; the 

 third not longer than the first joint of the flagellum ; flagellum with 11 joints, of which 

 the distal are the longest, and the central the shortest ; bristles longer than the joints. 

 The lower antennae have the first three joints curiously interlocked, directed forwards 

 along the lower margin of the head ; the fourth long, linear joint provided with a 

 rather long hinge, which enables it to bend backwards at a sharp angle ; the fifth joint 

 still more slender, not quite so long ; the flagellum of 22 joints. There are long, thin 

 bristles on the fourth and fifth joints of the peduncle, and on most of the joints of the 

 flagellum. 



Left mandible with seven teeth on the cutting-edge, and five on the secondary plate ; 

 in the spine-row nine spines with clean points, and more or less spinulose concave edges ; 

 molar tubercle irregularly four-sided, with several nearly straight cross rows of denticles. 



VOL. XII. — part VI. No. 3. — April, 1887. 2 g 



