75 



exhibits an unmistakable likeness to the family Sphceromidce, not represented in the 

 fauna of Norway, and I had, indeed, formerly combined the two. There are, however, 

 some distinguishing characters which make it advisable to keep the two families 

 apart. On tbe other hand, I find it quite inadmissible to associate this family 

 with the AseUota, as proposed by some authors. The full segmentation of the 

 metasome, the uniform structure of the pleopoda, and the lateral position of the 

 uropoda, prove it unquestionably to belong to the group FlabeUifera, as here de- 

 fined. The family comprises as yet but a single genus. 



Gen. LimnOria, Leach, 1815. 



Generic Characters. — Body oblong, rather convex above, with the segments 

 sharply marked off from each other. Cephalon comparatively short and blunt in 

 front, with the buccal mass very prominent below. First segment of mesosome 

 longer than the other, and partly advancing over the cephaloru Coxal plates on 

 the succeeding segments, rather large, deflexed, the posterior ones triangularly 

 produced. The 5 anterior segments of metasome with well-developed, laterally 

 projecting epimera; terminal segment broad, flattened above. Eyes wide apart, 

 lateral. Antennae with the flagella rather short. Mandibles very strong, cutting 

 edge terminating in a conically compressed, chisel-shaped point, molar expansion 

 wanting, palp rather small. Anterior maxillae with the masticatory lobe conically 

 tapering and coarsely spinous at the tip, basal lobe narrow, turned anteriorly, 

 and carrying 3 short, ciliated apical setae. Posterior maxillae terminating in 3 

 setiferous lobes, the innermost representing the masticatory lobe. Maxillipeds 

 slender, with the basal part rather elongated and narrow, masticatory lobe well 

 developed, palp composed of 5 flattened joints, epignath lanceolate, turned ante- 

 riorly. Anterior pairs of legs somewhat shorter than the posterior, dactylus in 

 all pairs provided inside with a secondary claw-like projection. Pleopoda with 

 the rami lamellar, and, excepting the last pair, densely fringed with setas. Uro- 

 poda with the outer ramus short, unguiform; inner, linear. 



Remarks. — This genus was established by Leach in the year 1815, to in- 

 clude the peculiar little creature, whose destruction of pile-work and other sub- 

 merged timber had long been known. He associated the genus with the Cymothoidw 

 and Sphceromidw, thus recognizing its true relationship. We know, as yet, of only 

 3 species, one of which, L. segnis Chilton, has been found off New Zealand, the 

 2nd, L. antarctica Pfeffer, at the South Georgian Islands, the 3rd being widely 

 distributed in the northern Ocean. 



