CRUSTACEA CASPU. 481 



form dactylus aduiits of being impinged, tluis constituting an imperfect 

 chela. 



The 2 anterior pairs of uropoda (fig. 15) have tiie outer ramus con- 

 siderably shorter than the inner, both being linear in form, and tipped by 

 numerous strong spines. 



The last pair of uropoda (fig. 16) are moderately elongated, projecting 

 considerably beyond the others. The outer ramus is somewhat flattened, 

 though not very broad, and gradually tapers distally. It is provided on the 

 outer edge with 2., on tlie inner with 3 fascicles of spines accompanied by 

 a few slender bristles, and has the terminal joint very narrow, and spiui- 

 form. The inner ramus is extremely small, and scale-like. 



The telson (fig. 17) is comparatively narrow, being almost twice as long 

 as it is broad, and scarcely tapering at all distally. It is divided by a deep 

 and narrow cleft into 2 halves, each of which carries, at the obtusely rounded 

 tip, 3 short spinules. 



Occurrence. — Of this form, some specimens are contained in the col- 

 lection of Dr. Grimm, having been taken as early as in the year 1871 by 

 Prof. Kessler, at Astrachan, from Astacus leptodactylus, and erroneously 

 labelled Gammarus pulex. Some other specimens, for the most part not 

 yet fully grown, were collected by Dr. Grimm in the bay of Baku. More- 

 over a single small specimen was taken last summer by Mr. Maximowicz, 

 in the bay of Karabugas. 



Fam. COROPHIIDiE. 



Gen. Corophium, Latr. 



Of this genus, wliich has previously been regarded as exclusively marine, 

 no less than 6 different Caspian species have been described by the author 

 in his 3rd article on the Amphipoda. A 7th species is now added, easily dis- 

 tinguishable from all the others. 



25. Corophium spinulosum, G. 0. Sars, n. sp. 



(PI. 12, tigs. 18—25). 



Specific Characters. — Body of the usual depressed form. Frontal edge 

 of cephalon not produced in the middle, lateral lobes narrowly rounded. 

 First pair of coxal plates with 4 slender apical bristles, and several smaller 

 ones anteriorly. Segments of urosome all well defined, and armed dorsally, 

 near the posterior edge, with a transverse series of slender spines. Superior 

 antennfe rather slender and elongated, 1st joint of the peduncle about same 

 length as the 2ud, and armed below with 2 distant spines, flagellum longer 

 than the peduncle. Inferior antennae, as usual, much stronger in male than 



^n3.-MaT. CTp. Sll. ol 



