358 



10. Parapleustes glaber (Boeck). 



(PI. 12U, fig. 1). 



ParnmpMthoe glabra, Boeck, Crust, amph. bor. & arct. p. 95. 

 Syn. : ParamphithoL- exigua, Goiis. 

 Pleustea glaber, Boeck. 

 Parapleustes gracilis, Buchholz. 



Body moderately slender, glabrous, with evenly-rounded back. Cephalon 

 exceeding in length the first 2 segments of mesosome combined, front produced 

 to a distinct, tliough not very large, rostral projection, latei'al corners acumi- 

 nate at the tip, poatantennal ones produced to a spiniform, anteriorly-curving 

 process. Anterior pairs ofcoxal plates considerably deeper than tlie body, the 

 first 3 pairs each with a very conspicuous dentiform projection at the infero- 

 posteal corner, anterior corner rounded; 4th pair obtusely truncated at the tip, 

 posterior projection nearly right angled; fith pair rather small, with the posterior 

 lobe but little deeper than the anterior. Last pair of epimeral plates of meta- 

 some produced at the lateral corners to a small, somewliat recurved, dentiform 

 projection, defined above by a small sinus. Eyes of moderate size, rounded oval 

 in form, pigment dark red. Superior antennae attaining about Vs of the length 

 of the body, 1st joint of the peduncle rather prolonged, much longer than 

 the other 2 combined, and produced at the end interiorly to a spiniform 

 projection, flagellum more than 3 times as long as the peduncle, and composed 

 of numerous articixlations, the 1st of which is rather elongated. Inferior 

 antennae somewhat exceeding half the length of the superior, last joint of 

 the peduncle longer than the penultimate one, flagellum scarcely twice as 

 long as the peduncle. Gnathopoda of moderate size and less unequal than 

 in the other species, propodos in both pairs oblong oval in form and 

 exceeding in length the 3 preceding joints combined, palm very oblique, 

 much longer than the hind margin, and having, below, 2 fascicles of strong 

 spines, carpal lobe narrowly rounded and densely setous. Pereiopoda 

 rather slender, basal joint of the 3 posterioi' pairs regularly oval in form, 

 and having the posterior edge distinctly serrated. Last jiair of uropoda 

 with the inner ramus nearly twice as long as the outer. Telson oblong oval 

 in form, nearly twice as long as it is broad, tip evenly rounded. Colour 

 rather variable, but generally whitish, variegated witli larger, often confluent 

 patches of a reddish brown hue. Length of adult female scarcely exceeding 6 .nm. 



RemarJiS. — The present form was at first announced by Boeck, at the 

 meeting of the Scandinavian naturalists in 18(50, under the name ot AnqMfhopsis 

 glabra, but subsequently referred to the genus Parampldtlw'v. In his great 

 work on the Northern Amphipoda it was more fully described and figured 



