268 



pair much narrower than in M. Solsbergi, with the anterior edge evenly 

 curved and the tip narrowly rounded; 3rd pair fully twice at deep as the 

 corresponding segment, and somewhat obliquely truncated as the tip; 4th 

 pair considerably larger than the 2 preceding pairs combined, and broader 

 than they are deep, distal edge but very slightly curved, posterior extremity 

 evenly rounded off. Last pair of epimeral plates of metasorae rather produced 

 at the lateral corners. Eyes not very large, rounded, pigment bright red, 

 Antennae comparatively short, the superior ones scarcely exceeding in length 

 the third part of the body, 1st joint of the peduncle about the length of 

 the cephalon, but somewhat shorter than the 2 succeeding joints combined, 

 flagellum scarcely as long as the peduncle, and composed of about 9 articula- 

 tions. Interior antennse about the length of the superior, the 2 outer joints 

 of the peduncle nearly equal-sized, flagellum scarcely exceeding the length 

 of the last peduncular joint. Anterior gnathopoda of normal appearance, 

 meral joint produced at the end inferiorly to a distinct setiferous projection, 

 propodos about the length of the carpus, but scarcely as broad, somewhat 

 tapering distally, and armed on the inferior edge with a single denticle 

 about in the middle. Posterior gnathopoda comparatively feeble in structure, 

 carpus produced at the end inferiorly to a rather large rounded lobe, densely 

 setiferous at the tip, propodos rather narrow, oblong quadrangular in form, 

 and slightly dilated distally, palm rather oblique, but shorter than the hind 

 margin and defined from the same only by an obtuse angle, its edge nearly 

 straight and quite smooth. Pereiopoda less strongly developed than in M. 

 Sfilsbergi; last pair with the basal joint much broader, and oval quadrangular in 

 form, meral joint not very much expanded, and prodiiced somewhat beyond the 

 middle of the carpal one. Last pair of uropoda with the basal joint shorter 

 than the other 2 combined, and armed with only 2 small denticles. Telson 

 quite unarmed, and very narrow, nearly three times as long as it is 

 broad, slightly constricted in front of the middle, tip obtusely pointed. 

 Colour pale greyish white, each segment having dorsally a slight 

 yellowish transversal band; ova in the marsupial pouch bluish. Length of 

 adult female 4 mm. 



Remarks. Boeck has apparently confounded this very distinct 

 species with M. Alcleri 1 ), from which it may easily be recognized, among other 

 characteristics, by the short equal-sized antennae, and by the very different 

 shape of the posterior gnathopoda. The specific name refers to the comparatively 

 feeble structure of the latter legs. 



The figs 4 and 4 k of PI. XVII in Boeck's great work, undoubtedly belong to the pre- 

 sent species, and not, as said in the text, to M. Alderi. 



