333 



dibles unusually large and strongly incrusted, having the cutting part simple, 

 not dentated, and the molar expansion well developed, palp rather slender, with 

 the middle joint less abruptly bent than in Halimedon. Maxillae nearly as in 

 that genus. Maxillipeds comparatively more fully developed, with the palp 

 considerably larger. Gnathopoda rather unequal, the posterior ones being much 

 more slender and elongated than the anterior, both pairs with the carpus 

 rather elongated, and forming inferiorly a more or less distinct setous expan- 

 sion, propodos not very large, with the palm very oblique and armed below 

 by an unusually long and slender spine. Pereiopoda, uropoda and telson of 

 the usual structure. 



Remarks. - - I have felt justified in establishing this new genus, in order 

 to include the 2 rather anomalous species described by Boeck as Halimedon 

 longimanus and H. Saussurei, both of which agree in some characteristics not 

 found in the other species of Halimedon; thus, in the quite rudimentary con- 

 dition of the visual organs, the non-produced frontal part of the cephalon, 

 the rather unequal structure of the gnathopoda, and finally the unusually 

 large size of the mandibles. As a 3rd species of this genus I propose to 

 describe the Halimedon obtusifrons of Hansen, which, though differing rather 

 conspicuously from the. 2 above-named species as to outward appearance, yet 

 shows some anatomical characteristics in common with them. As all 3 species 

 are very pronounced deep-water forms, I have chosen the above generic 

 denomination, which, at the same time, is intended to express the affinity of 

 the genus with Halimedon. 



29. Bathymedon longimanus (Boeck). 



(PI. 117). 

 Halimedon longimanus, Boeck, Crust, anipb. bor. & arct. p. 90. 



Body rather slender and somewhat compressed, with very thin and pel- 

 lucid integuments. Cephalon not fully attaining the length of the first 4 

 segments of mesosome combined, and produced in front to a small acute rostral 

 projection reaching about to the middle of the basal joint of the superior 

 antennae, lateral parts forming on each side a rather deep and broad obtuse- 

 angled expansion, covering over the whole basal part of the inferior antennae, 

 its anterior edge slightly convex in the middle. First pair of coxal plates 

 obliquely expanded, in their outer part, distal edge nearly straight; the 2 

 succeeding pairs rather narrow and nearly equal in size; 4th pair much larger, 

 and about as deep as the corresponding segment, infero-posteal corners some- 

 what produced, though obtuse at the tip; 5th pair rather broad, with the 

 posterior lobe somewhat projecting. Eyes inconspicuous., and replaced by a 



