371 



backwards; the 2 last pairs each with a small dentiform projection posteriorly. 

 £3-63 rather large and prominent, ronnded, pigment dark brown. Superior 

 antennae nearly attaining half the length of the body, 1st joint of the peduncle 

 about the length of the other 2 combined, and produced at the end anteriorly 

 to a large spiniform projection, flagellum about 3 times as long as the peduncle, 

 and composed of numerous short articulations. Inferior antennas much longer 

 tlian the superior, joints of tlie peduncle produced at the end to triangular 

 dentiform projections, flagellum extremely slender, and nearly 4 times as long 

 as the peduncle. Gnathojjoda with the propodos about the length of the 2 

 preceding joints combined, and rather narrow, but very sligb.tly widening 

 distally, palm nearly transverse, dactylias small. Pereiopoda edged with 

 fascicles of short spines, basal joint of the 3 posterior pairs divided 

 posteriorly into 2 acuminate lappets. Last pair of uropoda a little pi'ojecting 

 beyond the others, rami more than twice as long as the basal part, and 

 edged with small denticles and a few minute bristles. Telson oblong subtrian- 

 gular in form, gradually tapering distall}^ tip narrowl}' truncated. Body 

 light straw-coloured, more or less mottled with a brownish pigment. Length 

 of adult female 19 mm. 



Eemarks. — This peculiar form was at first described by Lepechin, as 

 early as in the year 1778, under the name of Oniscus cuspidatus. In 1835 it 

 was redescribed by Owen under another name, viz, Acanthosoma hystrix, 

 and most sxibsequent authors have adopted the latter specific name, which 

 however must cede to the much older one proposed by Lepechin. The external 

 appearance of this animal is so highly characteristic, by its densely spinous 

 armature, as to be at once distinguished from any of the other northern 

 Amphipoda. In this respect it bears a perplexing resemblance to the above 

 mentioned form described by the Eev. Mr. Stebbing from the Challenger 

 Expedition under the name oiAcanthechinns trkarinatits. The latter is, however, 

 apparently generically distinct, and, among other characteristics, very markedly 

 distinguished by the extremely slender and feeble gnathopoda. But in any 

 case it cannot, in my opinion, be separated in a different family. 



Onurrerice. — I have myself only met with this interesting form on 

 the coast of Finniark, where in some places it would seem to be rather com- 

 mon in moderate depths. A considerable number of specimens were thus 

 collected, many years ago, by my late father and Dr. Danielssen in the 

 Komagfjord, west Finmark, as also at Hammerfest and Vadso, where, more- 

 over, at a still earlier date, it was found by Prof. Loveu. It has, however, 

 recently been found in a very distant locality, viz., in the Trondhjemsfjord, 

 where several specimens were collected from deep water by Mr. Storm, curator 

 of the Museum in Trondhjem. 



