REPORT ON THE SCHIZOPODA. 141 



either side, near tlie extremity, a very slender, non-ciliated bristle. Finally, the last 

 joint, representing the terminal jiart in the preceding legs, is exceedingly narrow, and 

 bears four similar bristles, one of which issues from the outer edge, the other three from 

 the tip ; one of the latter is extremely elongate. 



The penultimate pair of legs (fig. 15) are still smaller and simpler in structure, with 

 the endopod consisting of only two joints of almost equal size, the terminal one somewhat 

 curved, and provided at tlie tip with four remarkably long and slender, non-ciliated 

 bristles. The exopod in this as well as the preceding pair is very small, though with 

 both its sections well defined. 



The last pair of legs (figs. 16, 17) are quite rudimentary, each forming merely an 

 ovoid, setiferous lamella (exopod), originating from a short basal part connected with 

 the corresponding gill-stem. 



The gills (see fig. 2) exhibit on the whole a rather simple structure, all, except the 

 last pair, forming single stems, more or less expanding at the tip, and bearing a regular 

 series of digitiform gill-lobules. On the two first pairs two such lobules only are present ; 

 on the succeeding pairs the number gradually increases from four to eight. The last pan- 

 (figs. 2, 16, 24) are somewhat more complex, exhibiting the two usual divisions, the outer 

 of which is the larger, and bears three or four secondary gill-branches. 



The pleopoda in the female exhibit the usual structure. In the male, the two 

 anterior pairs are slightly modified, the inner plate having a sexual or copulatory 

 appendage. On the first pair, this appendage (figs. 25, 26) consists apparently of two 

 portions, the outer bearing at the tip two rather short and somewhat hamate processes, 

 together with a short curved spine, the inner portion simple lobular. On the second 

 pair, the appendage (fig. 27) is comparatively large, projecting far beyond the principal 

 plate, and exhibits at the somewhat dilated extremity several twisted lobes. 



The telson (see fig. 18) has the usual slender form, tapering towards the apex, which 

 terminates in a sharp point. The subapical spines are not very large, projecting but 

 slightly beyond the tip of the telson, and perfectly smooth. Furthermore, two pairs of 

 small denticles occur on the dorsal face of the telson. 



The uropoda (ibid.) are likewise quite normal in structui-e, having the inner plate 

 somewhat longer than the outer, and reaching nearly to the tip of the telson. 



The luminous apparatus, so uniformly developed in most other Euphausiid£e, exhibits 

 in this genus certain well-marked peculiarities. Thus the globules are considerably 

 reduced in number, only three of them being developed, viz., one odd one between the 

 bases of the first pair of pleopoda, and a pair of lateral globules at the bases of the 

 penultimate pair of legs (see figs. 1, 19). On the other hand, the latter globules attain 

 in the male (figs. 20, 23) an extraoi'dinary development, being more than twice as large 

 as those in the female. Moreover, a supplementary lens, formed, it would seem, by a 

 thickening of the outer integument, is subjoined at some distance from the globule, and 



