(sxxv)] τ CRUSTACEA CASPIA. 65 
with a strong spiniform projection; posterior lip (fig. 7) of the usual shape. 
Mandibles (fig. 8 & 9) comparatively large, with the palp well-developed 
and edged with ciliated setae. First pair of maxille (fig. 10) having the 
masticatory lobe very narrow and attenuated, exognath forming only a small 
laminar expansion ciliated at the edge. Second pair of maxillæ (fig. 11) 
with the terminal joint of the palp oval in form, and having only a very 
restrieted number of setze on the outer edge, exognath not very large, and 
triangular in form, with comparatively few marginal setze. Maxillipeds (fig. 
12) with the basal and masticatory lobes well-developed. Gnathopoda (fig. 
13) extremely robust, with the joints very much dilated, the meral and 
tarsal ones being much the largest, terminal joint (fig. 14) scarcely lamellar, 
and having at the tip several very strong and claw-like spines. Pereiopoda 
short and stout, the 2 anterior pairs (fig. 15) with the tarsal part well 
defined, and composed of 3 articulations; the 4 posterior pairs (fig. 17) having 
the tarsal part quite rudimentary, and armed with strong, claw-like, incurved 
spines, dactylar joint in the former (fig. 16) normal, in the latter (fig. 18) 
nearly obsolete. Pleopoda of male (fig. 22, 23) modified in a similar manner 
as in the 2 preceding genera. Telson (fig. 20) not very large, and triangu- 
lar in form, tapering to an obtuse point bearing 2 strong spines, lateral 
edges spinulose. Uropoda (fig. 19) with the inner lamella but little shorter 
than the outer. 
Remarks. — The present new genus is chiefly distinguished by the very 
remarkable reduction of the terminal part in the 4 posterior pairs of perei- 
opoda, which thereby look as if they were mutilated. The structure of the 
antennal scales somewhat resembles that in the genus Austromysis, but the 
telson is constructed upon a totally different type, not being incised poste- 
riorly, but terminating in an obtuse point. Also in the structure of the oral 
parts and that of the gnathopoda, the genus exhibits several well-marked 
differences from its nearest allies. The genus is as yet only represented by 
a single species, to be described below. 
7 Katamysis Warpachowskyi, G. Ο. Sars, n. sp. 
(Pl. VIL) 
Specific Characters. — Body (see Pl. VIT, fig. 1 and 21) ofrather robust 
form, and having the anterior division somewhat tumefied. Carapace deeply 
emarginated posteriorly, leaving the dorsal part of the last 2 segments of 
mesosome quite uncovered, cephalic part fully as broad as the 1* segment 
of metasome, and having the anterior edge (see fig. 2) rather produced in 
the middle, forming a distinct, nearly right angle, which, however, does not 
quite obtect the frontal spine. Metasome not much prolonged, and rather 
Mélanges biologiques. T. XIII, p. 413. 5 
