302 G. 0. SARS, [N. S. ıv 
The metasome, or tail, exhibits the usual slender cylindrical form, and 
is composed of 6 sharply-defined segments, successively increasing in length 
to the penultimate one, which is the longest. Their posterior edge is some- 
what thickened, and distinctly emarginated both on the dorsal and ventral 
face, whereas it laterally projects as an obtuse angle. Dorsally these segments 
have 2 longitudinal keels, which, at the posterior part of each segment, are 
elevated to rounded crests. The last segment is considerably shorter than 
the penultimate one, and is somewhat flattened, becoming broader at the 
extremity, to which the uropoda and telson are articulated. 
The integuments are moderately strong, and exhibit everywhere a distinct 
squamous structure. On the dorsal projections the squamulæ are somewhat 
projecting, giving the edges a finely serrulated appearance (see fig. 2). 
The eye, as in most other Cumacea, constitutes a single median organ 
occupying the ocular lobe. It contains 3 distinct and highly refractive corneæ, 
one median and 2 lateral, all imbedded in a common pigmentary mass. 
The superior antennæ (fig. 3), which project anteriorly from the sinus 
between the pseudo-rostral projection and the antero-lateral corners of the 
carapace, are rather slender, and consist each of a 3-articulate peduncle and 
2 flagella. The 1st joint of the peduncle, which to a great extent is hidden 
between the lobes of the carapace, is rather thick and muscular. It carries 
at the end exteriorly a single plumose seta, and has the inner edge finely 
ciliated. The 2nd joint is of about the same length as the 1st, but much narrower, 
and bears on the outer edge 5 strong bristles and a single one at the end 
inside. The 3rd joint is still narrower, and also shorter than the 2nd, and 
nearly linear in form. Of the flagella, the one (the exterior) is well developed, 
about the length of the last joint of the peduncle, and consists of 3 well 
defined articulations, the 1st of which is much the largest. It carries at the 
end 2 band-like sensory appendages, one of which issues from the penulti- 
mate articulation, the other from the extremely small last joint, which 
moreover bears at the tip a short simple bristle. The inner flagellum is 
quite rudimentary, consisting of a single very minute joint carrying at the 
tip a few fine bristles. 
The inferior antennæ (fig. 4) are completely hidden between the antero- 
lateral corners of the carapace, and can only be seen by dissection. They 
consist each of a small conically tapering stem, without any distinct articu- 
lation, and tipped with a single rather large plumose seta. 
The anterior lip (fig. 5) forms a rounded flap covering over the oral 
orifice. It is strengthened by several chitinous stripes, and has the posterior 
edge slightly insinuated and finely ciliated. 
Mélanges biologiques. T. XIII, p. 466. 
