SS THE VOYAGE OF H.M.S. CHALLENGER. 



well-marked rounded crest above ; rostral projection very short. Caudal segments with 

 fully developed epimera ; third segment jutting out posteriorly as a strong dorsal spine, 

 pointing backwards. Last segment rather elongate ; preanal spine obsolete. Eyes 

 very lar"e, pyriform. Autennular peduncle without any dorsal lappet. Antennal 

 scale oblong, apex narrowly truncate, outer angle unarmed. Telson elongate, taper- 

 ino-, with two pairs of dorsal denticles ; subapical spines strong and diverging, 

 smooth. Inner plate of uropoda scarcely at all projecting beyond outer. Length 

 reaching 14 mm. 



Remarks. — Tiiis species somewhat resemljles Euphausia splendens. It may, however, 

 at once be distinguished by the strong spiuiform projection of the third caudal segment, 

 a character from which the specific name is derived. 



Description. — The specimens in the collection are not in the best state of preservation, 

 l)ut yet distinctly exhibit the prominent characters of the species. AU of them are 

 females, and the largest specimen has a length of about 14 mm. 



The form of the body (see PI. XV. fig. 9) approximates, on the whole, a good deal to 

 that of Euphausia sjilendens, the tail being powerfully developed and weU nigh twice 

 the length of the anterior division. 



The carapace has on either side a distinct lateral denticle, placed about the middle of 

 the inferior margin, or above the point of insertion of the second pair of legs. The 

 anterior part exhibits a very conspicuous' rounded dorsal crest, and juts out as an 

 exceedingly short rostral projection, reaching but little beyond the ocular segment. 



The caudal segments have rather deep epimera, of a rounded form, except the last 

 pair, which are triangular. The third segment juts out dorsally into a well-marked, 

 mucroniform spine, pointing backwards, and at the end of the penultimate segment 

 a simdar but very small projection occurs. The last segment is rather produced, 

 about as long as the two preceding ones taken together, and would seem to lack the 

 preanal spine. 



The eyes (see fig. 10) occur very large and protruding, pyriform, with the cornea 

 greatly expanded. 



The autennular peduncle (ibid.) does not exhibit airy distinct dorsal lappet. A 

 very small protrusion of the anterior margin of the basal joint may, however, possibly be 

 considered the rudiment of such a part. 



The antennal scale {ibid.) reaches a little beyond the second joint of the auten- 

 nular peduncle, exhibiting an oblong form, with the apex narrowly truncate and the 

 outer angle unarmed. 



The oral parts and the legs would not seem to difter materially from those of 

 Euphausia splendens. 



The telson (see fig. 11) is rather elongate, and tapers graduaUj- toward the apex, 

 which is lanceolate and pointed. The subapical spines are strong and di^'erging, but 



