REPOET ON THE SCHIZOPODA. 81 



with the Eiqihausia splendens of that author, or belong to some other alUed species. 

 Meanwhile, assuming the species so designated by Dana to Ije almost certainly repre- 

 sented in the rich collection of the Challenger Euphausiida;, I hold this form to be the 

 one most properly referaljle to that species. From both the preceding species the 

 present form may be readily distinguished by its robust body, the very short rostral 

 projection, and the strong, curving setse that spring from the basal joint of the 

 antennulae. 



Description. — The length of the largest specimen reaches about 18 mm., and the 

 species attains accordingly a somewhat larger size than Euphausia 2)eUucida. 



The general form of the body (see PL XIII. fig. 7) would, on the whole, appear to be 

 somewhat shorter and more thickset than in the two preceding species, and this feature, 

 too, is obvious from the figure given by Dana, at least as comiJared with that of Euphausia 

 j)ellucida. 



The carapace, as in Euphausia similis, exhibits on either side a single lateral 

 denticle about the middle of the lower margin, or rather just above the point of insertion 

 of the second pair of true legs. Its anterior part has above a well-marked keel, and the 

 frontal margin forms in the middle a very slight rostral projection, or rather an acute 

 angle, scarcely projecting beyond the ocular segment. 



The caudal segments are smooth above and furnished with rather small evenly 

 rounded epimera. The last segment is appreciably longer than any of the preceding, and 

 has the preanal spine (fig. 17), as in Euphausia similis, quite simple or unguiform, though 

 somewhat stronger than in that species. 



The eyes (see fig. 15) are very large and projecting, pyriform, with the cornea much 

 expanded. 



The antennular peduncle (fig. 8) is more particularly distinguished by the total absence 

 of any dorsal leaflet or lobe, whereas a bunch of strong, curving bristles is seen to spring 

 from the dorsal face of the basal joint. 



The antenna! scale (fig. 9) agrees in its form comparatively well with that in 

 Euphausia pellucida, though perhaps a trifle more elongate. The basal spine, as in that 

 species, is distinctly denticulate, but very much smaller. 



The mandibular palp (fig. 10) exhibits none of the short spiniform bristles peculiar to 

 Euphausia pellucida. 



The first pau" of maxillae (fig. 11) have the exoguath relatively larger, and more 

 oblong in form. 



The second pair of maxillae (fig. 12) are chiefly distinguished by the large size and 

 ovoid form of the terminal joint. 



The copulatory appendages of the two first pairs of pleopoda in the male (see figs. 13, 

 14) exhibit on the whole a structure considerably approximating to that in Euphausia 

 similis. Still, however, a few well-marked difi"erences may be found, more especially in 



(ZOOL. CHALL. EXP. PART XXXVII. 188.').) Oo 11 



