412 G. 0. SAKS, [T. XIII 



cated antenna! scales, and by the comparatively more slender pereiopoda. 

 It is also of rather inferior size. Mr. Czerniavsky records also of this spe- 

 cies 2 forms or varieties; the one ; „forma typica" is said to have the apical 

 sinus of the telson very shallow or scarcely distinct, the other, „forma 

 truncata", to have the telson nearly transversely truncated at the tip. In 

 the figures, however, the telson is everywhere represented as quite trans- 

 versely truncated, without any trace of an insinuation of the apical edge. 



Occurrence. — A few specimens, males and females, of this species were 

 contained in the collection of Mr. "Warp achovv sky, and occurred at Stat. 

 15, together with Paramysis Baeri. According to Mr. Czerniavsky, 5 

 specimens of the typical form were collected by Prof. Kowalevsky at Pe- 

 trowsk (?). 



Distribution. — Black Sea: a single specimen of the „forma truncata", 

 extracted from the ventricle of a Perca fluviatilis, caught at Odessa (Czer- 

 niavsky). 



6. Mesomysis aberrans, Czern. 



Mesomysis àberrans, Czerniavsky, 1. c. fasc. 2, p. 54, PI. XXIII, figs. 16—21. 



Remarks. — I have not myself had an opportunity of examining this 

 form, but it may be here mentioned, as it is stated to occur in the Caspian 

 Sea. To judge from the description and figures given by Mr. Czerniavsky, 

 this species is very nearly allied to M. intermedia, differing, however, by 

 the anterior edge of the carapace being so much produced in the middle as 

 to nearly quite obtect the frontal spine, and by the apical edge of the telson 

 being not transversely truncated but even somewhat convex, though armed 

 in the usual manner. 



Occurrence. — The specimens examined by Mr. Czerniavsky, were 

 collected by Prof. Kowalevsky at Petrowsk (?). 



Gen. 3. Katamysis, G. 0. Sars, n. 



Generic Characters. — Form of body (see PI. VII, figs 1 and 21) short 

 and stout. Carapace imperfectly obtecting the posterior part of mesosome, 

 and having the cephalic part rather short, with the anterior edge angularly 

 produced in the middle; frontal spine present. Eyes (see fig. 2) scarcely 

 expanded distally. Superior antennae (fig. 3) of the usual structure, male 

 appendage very large and densely hirsute (see fig. 21). Inferior antennae 

 (fig. 4) with the basal part scarcely at all produced at the outer corner, 

 scale very short, rhomboidal in form, with the outer edge smooth and ter- 

 minating in a dentiform projection, inner corner much produced and exhi- 

 biting â distinct apical segment (fig. 5). Anterior lip (fig. 6) armed in front 



Bulletin N. S. IV (XXXVI) p. 64. 



