250 

 9. Metopa Alderi (Sp. Bate). 



(PI. 86). 



Montayua Alderi, Sp. Bate, Cat. Amph. Brit. Mus. p. 57, PL VIII, fig. 6. 

 Syn: Leucothoe norvegica, Lilljeborg (male). 

 Metopa clypeata var. Boeck (male) 



Body rather higli and compressed, but with the back broadly rounded. 

 Cephalon scarcely twice as long as the 1st segment of mesosome, lateral 

 corners forming on each side a rather broad lobe truncated at the tip. 

 Second pair of coxal plates rather narrow, and obliquely curved in front, 

 outer part tapering to an obtuse point; 3rd pair scarcely expanded distally, 

 and about twice as deep as the corresponding segment ; 4th pair much 

 larger than the 2 preceding pairs combined, distal edge rather oblique, and 

 evenly curved. Last pair of epimeral plates of metasome but very little 

 produced at the lateral corners, and nearly rectangular, posterior edge 

 straight. Eyes rather large, rounded oval, with well-developed visual 

 elements and dark red pigment. Superior antennse scarcely half the length 

 of the body, and much shorter than the inferior, reaching in female a little 

 beyond the peduncle of the latter, 1st joint of the peduncle as long as the 

 other 2 combined, and equalling the length of the cephalon, flagellum about 

 half as long again as the peduncle. Inferior antennse rather strong, especially 

 in the male, the 2 outer joints of the peduncle being strongly chitinized 

 and rather elongated, ilagellum comparatively small, and more or less 

 abruptly curved. Anterior gnathopoda rather small, meral joint not very 

 much produced at the end inferiorly, propodos about the length of the 

 carpus, and scarcely broader, its inferior edge but very slightly curved in 

 the middle. Posterior gnathopoda rather powerful, especially in the male, 

 meral joint continued inside, above the terminal articulation, as a thin 

 triangular lamella, somewhat overlapping the upper edge of the carpus, 

 propodos in female nearly as long as the basal joint, and oblong oval in 

 form, palm oblique, about as long as the hind margin, and defined by a 

 dentiform projection armed with 2 small spinules, its edge somewhat flexuous, 

 front part armed with about 8 strong denticles diminishing in size anteriorly, 

 hind part deeply sinuated; propodos in male much larger than in female, 

 and having inferiorly, about in the middle, a deep and broad sinus, defined 

 behind by an acuminate projecting lappet, anterior part of the palm forming a 

 lamellar expansion divided into 5 (j strong denticles. Pereiopoda moderately 

 strong, meral joint of the 3 posterior pairs somewhat expanded, and 

 considerably produced at the infero-posteal corner, basal joint of last pair 

 scarcely larger than that of the penultimate pair, and slightly widening 

 below. Last pair of uropoda with the basal joint nearly as long as the 



