CRUSTACEA CASPIA. 183 



constituted his special study, merely because some authors erroneously ap- 

 plied his name for the establishment of spurious genera. 



The systematic position of this remarkable genus would seem, at the 

 first sight, to be somewhat doubtful. In the robust form of the body, the 

 poor development of the metasome and urosome, as also in the comparatively 

 short caudal appendages, it rather much reminds of the Orchestiidae. But 

 the oral parts are constructed upon the very same type as in the true 

 Gammaridae, and the branchial lamellte exhibit the same characteristic 

 pedunculated appearance as in this family. Moreover the superior antenufe 

 are considerably longer than the inferior, differing, however, very markedly 

 from those in tlie other Gammaridae in the want of a true accessory ap- 

 pendage. Notwithstanding this and other divergences from the Gammaroid 

 type, I am inclined to believe, that this geaus ought more properly to be 

 placed within the Gammaridae^ tliough constituting a rather anomalous 

 membre of the family. 



Besides the species described below, Dr. Grimm has distinguished 2 

 otlier species of this genus under the names B. nasuta and B. hystrix. Both 

 these species are, however, founded upon quite immature specimens, the 

 first-named agreeing exactly with young specimens of B. spinosa, as figured 

 PI. II, fig. 10; and the other only differing in the dorsal prominences of 

 the segments being somewhat stronger and elevated to acutely triangular 

 projections. In my opinion both these supposed species ought to be with- 

 drawn, the genus being at present only represented by a single species. 



1. Boeckia spinosa, Grimm. 



(PI. I aud II). 



Specific Characteristic. — -Body in female extremely stout and very tumid, 

 in male somewhat more slender and less broad; back obtusely carinated 

 throughout, with the segments slightly projecting dorsally; mesosome having 

 on each side, at the junction of the coxal plates, a row of spiniform pro- 

 cesses, those of 5th segment being very large and terminating in a sharp 

 point, the others comparatively small aud obtuse at the tip; segments of 

 metasome each with a pair of subdorsal, upturned processes, which however 

 in the 1st segment are rather small aud tuberculiform ; 1st segment of uro- 

 some overlapping dorsally the succeeding ones and terminating in a rather 

 large, hooked, median projection, having besides, as the segments of meta- 

 some, a pair of upturned subdorsal processes. Cephalou slightly keeled dor- 

 sally, rostrum horizontally projected and triangularly pointed, latei'al pro- 

 jections longer than the rostrum, and diverging to each side nearly at a 

 right angle. Anterior pairs of coxal plates much deeper than the corres- 



$n3.-MaT. CTp. 183. 5 



