198 «■ 0. SAKS. 



close to the anterior extremity of the cephalou. Antenna? nearly equal-sized 

 and rather short, scarcely exceeding in female % of the length of the hody. 

 Gnathopoda nearly as in the preceding species, and exhibiting a similar dif- 

 ference in the two sexes. Pereiopoda likewise of a structure very similar to 

 that in the said species, though being perhaps a little more slender. Last 

 pair of uropoda not nearh- so much elongated as in G. costata, the outer 

 ramus lieing far less fully developed and also less ])ronouncedly foliaceous 

 in character. Telson rather short, cleft narrow and extending nearly to the 

 base, terminal lobes obtusely rounded and anned witli several spines both at 

 tlie tip and the outer edge. Length of adult female 14 nnu., of male 18 ram. 

 Bemarks. — There cannot be any doubt that tlie above-characterised 

 form is that recently described by Mr. Sowiusky from the Asow Sea as 

 Gammarus Kmnezowi. It is, however, certainly not a ti'ue (rammarus, but 

 ought, in spite of the rather different armature of the body and the less 

 fully developed last pair of uropoda, to be referred to the same genus as the 

 ])receding species, with which it agrees very closely in nearly all anatomical 

 details. It is a very easily recognizable form, being highly distinguished by 

 the peculiar subdorsal, mammilliform pi'ojections, on which cause I at first 

 noted it under the provisional name of PallasieUa mainmilliftra. 



Description of the feiiiiile. 



Adult ovigerous specimens attain, when fully extended, a length of 

 about 14 mm. 



The forai of the body (see fig. 1) is rather slender and compressed, 

 though perhaps not to such a degree as in the pi-eceding species. As in the 

 latter, all the integuments are highly incrusted, and the segments sharply 

 marked off from each other. 



The mutual longitudinal relation of the several body-divisions is about 

 as in that species, exce])t that the urosome is somewhat shorter. The body 

 is generally more or less strongly curved, and lias the back rounded off, not, 

 as in the preceding species, carinated. On the other hand, there occurs along 

 the back a double series of subdorsal prominences (one pair in each segment), 

 which anteriorly are very low and tuberculiform, but farther back, on the 

 last 2 segments of mesosome and those of metasome, assume a distiuctly 

 mammilliform shape, and, when the animal is viewed laterally, considerably 

 project beyond the dorsale line. The lateral parts of the 5 anterior segments 

 of the mesosome are, moreover, just above the junction of the coxal plates, 

 produced to very conspicuous laterally projecting, luberculiform prominences, 

 best seen in a dorsal view of the animal (com]), fig. 1 3). The segments of 

 the urosome are smooth above, without any jirojections, but, as in most 



41113. -MaT, cTp. 19S. 20 



