67 
Distribution .—Greenland (Kro'yer), Atlantic coast of North America 
(Verrill), Spitsbergen (Norw. North Atl. Exped.), the Kara Sea (Stuxberg), Skage¬ 
rak and Kattegat (Meinert). 
Gen. 4. Leptostylis, G. 0. Sars, 1869. 
Generic Characters. — General form of body that of Diastylis, being some¬ 
times very slender, sometimes rather robust, anterior division (at least in female) 
considerably tumefied and sharply marked off from the tail. Eye wanting. Superior 
antennae in female about as in Diastylis, in male conspicuously transformed, the 
peduncle being greatly dilated, claviforin, and clothed at the end with numerous 
diverging sensory filaments forming a dense brush, which almost conceals the 
flagella. Inferior antennae in male much more feebly developed than in Dia¬ 
stylis, and scarcely exceeding the anterior division of the body in length. Oral 
parts and anterior pairs of legs about as in Diastylis. Third and 4th pairs of 
legs in female with a very small, though distinct biarticulate appendage (rudi¬ 
mentary exopodite) outside the basal joint. Pleopoda in male less fully developed 
than in Diastylis. Uropoda with the rami very slender, the inner one being much 
the longer, and distinctly 3-articulate. Telson remarkably short, with only a 
single pair of lateral spinules. 
Remarlcs. — This genus was established in the year 1869 by the present 
author, to comprise some species formerly referred by him to the genus Diastylis, 
but, on a closer examination, found to differ in certain characters rather con¬ 
spicuously, especially as regards the structure of the antennae and pleopoda of the 
male. Another distinguishing character of the female, at first overlooked, is the 
presence of rudimentary exopodites on the 3rd and 4th pairs of legs, like those 
found in the genera Lamprops and Hemilamprops. The generic name Leptostylis 
is derived from the unusually slender rami of the uropoda; and the very short 
telson, with its single pair of lateral spinules, also forms an easily recognizable 
character of the present genus. We know as yet of 6 species, 4 of which belong 
to the Norwegian fauna, and will be described below. Moreover, Dr. J. Bonnier 
has recorded a form from the Gulf of Gascogne as Leptostylis longicaudata, which 
however, in my opinion, cannot properly be referred to the present genus, 
in spite of its being provided with rudimentary exopodites on the 3rd and 4th 
pairs of legs. 
