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Remarks. The type of this family is the peculiar genus Mnnna of Kroyer,
with which several other genera may be conveniently associated, to form a rather
well-defined group of Ascllota. From the laniridw, these Isopods may be easily
distinguished by the comparatively short and stout body, which,
unlike the
body in that family, is conspicuously narrowed behind, with the 3 posterior
segments of the mesosome much smaller than the 4 anterior ones, and the caudal
segment ob-pyriform in shape. Besides the 4 Norwegian genera treated of below,
the following genera may with certainty be referred to this family: Leptaxpidia
Bate & Westw., NeaseUus Beddard, Astrurus Beddard, Munnclla Bonnier, and
Haliacris Pfeffer. The last-named genus, however, is, scarcely different, generic-
ally,
from Munna.
Gen. 1. Munna, Boeck, 1839.
? Syn: Haliacris, Pfeffer.
Generic Characters. Body sub-pyriform in shape, with the dorsal face some-
what vaulted, and the last 3 segments of mesosome very small, with the lateral
parts curving more or less posteriorly. Cephalon very broad, with the frontal
margin obtusely produced. Caudal segment narrow, ob-pyriform, and very sharply
defined from the mesosome. Eyes distinct, placed on the tips of greatly produced
lateral projections of the head. Superior antenna1
comparatively small; inferior
antennae, on the other hand, very much elongated, with the peduncle 5-articulate,
the 2 outer joints long and slender. Mandibles with the cutting part divided
from the cylindrical molar expansion by .a deep incision, palp well developed.
1 st pair of legs in female comparatively small, imperfectly subcheliform, in male
more strongly developed, and sometimes of quite an extraordinary size. The re-
maining legs rapidly increasing in length, with the carpal and propodal joints
much elongated and edged with spines, dactylar joint small, bi-unguiculate. Middle
piece of male operculum rather narrow, snblinear. truncated at the tip. Uropoda
very small, simple.
Remarks. This genus was established by Kroyer in the year 1839, to
include a peculiar Tsopod found by him off the Norwegian coast. Subsequently
several additional species were detected by different authors, and the relation of this
genus to other Isopoda was more fully recognized. The external appearance is rather
peculiar, the apparently stalked eyes especially being very striking. In ovigerous
females, moreover, owing to the greatly projecting incubatory pouch, the fore-part of