——— 
288 THE SCHIZOPODA. 
Remarks.— The reference of this larva to EZ. distinguenda H. J. H. is certain, 
because I have a nearly complete series of the following stages of development 
and growth up to the adult specimens. The larvae of the stage described are 
distinguished from those of other species by the combination of possessing a 
slender body, a high and anteriorly steep dorsal keel and somewhat long eye- 
stalks. A comparison between the larvae just described with the corresponding 
stage described and figured by Sars as belonging to E. pellucida (“ Challenger ” 
Rept., pl. 29, fig. 7 and pl. 30, fig. 40) is not without interest. In certain respects 
Sars’s larva is more, in other features less, developed than the larva of #. dis- 
tinguenda; E. pellucida has the second pair of thoracic legs considerably longer 
than L. distinguenda, and the last pair of pleopods with both rami setiferous, 
while the telson has still seven terminal spines and the antennular flagella are a 
little less developed than in #. distinguwenda.— Similar cases of differences in 
the development between various species of the genus Euphausia have been 
pointed out in my paper on the Schizopoda of the Belgian Antarctic Expedition. 
Nyctiphanes simplex H: J. Hansen. 
Plate 12, figs. 3a-3f. 
A. Intermediate Furcilia-Stage (figs. 3a—3d).— The frontal plate (fig. 3b) 
very large, somewhat less than twice as broad as long, longitudinally concave 
and anteriorly cut off, with the front margin about half as long as the basal 
breadth of the plate and conspicuously concave but not angular at the middle; 
the antero-lateral angles feebly produced, acute-— The carapace has a well- 
developed tooth on the lateral margin, while the usual dorsal keel is very short 
and low, placed a little farther from the end of the frontal plate than from the 
posterior margin. ; 
The eyes are extremely large with moderately long stalks.— The antennulae 
are very thick; the process from first peduncular joint reaches beyond the middle 
of the third; second and third joints slightly longer than broad; the upper 
flagellum thick, nearly conical, unjointed and a little longer than the lower.— 
Antennae with the rami subsimilar in shape, but the exopod a little shorter than 
the endopod.— Maxillipeds (mxp.) with the exopod a little shorter than the 
endopod.— First pair of thoracic legs scarcely as long as the maxillipeds, with a 
rudimentary exopod and a small two-branched gill; the endopod has one dis- 
tinct and two indistinct articulations. Second pair half as long as the first, 
with a rudimentary branchia; third pair quite rudimentary. 
First and second pairs of pleopods with the exopod well developed, seti- 
