116 G. 0. SARS. CRUSTACEA. [norw. pol. exp. 



sharply marked off from the preceding one, with which it forms a very 

 movable articulation, whereas it is firmly connected with the 1st caudal 

 segment, so as apparently to form part of the tail. It is also much narrower 

 than any of the preceding segments, and only very slightly dilated distally. 



The tail proper (fig. 14) is exceedingly narrow, almost rod-like, and equals 

 in length about % of the anterior division. It is composed of 4 well-defined 

 segments besides the caudal rami, all being perfectly smooth, without any 

 traces of the circlets of denticles found in the other 2 species at the posterior 

 edges. The genital segment is much the largest, occupying about Vs of the 

 length of the tail. It is slightly dilated in its anterior part, and, as in Onccea, 

 has the genital orifices situated somewhat dorsally. None of the specimens 

 found were ovigerous; but there cannot be any doubt that the ova in the 

 present form, as in L. squillimana, are congregated within a single dorsal 

 ovisac. The anal segment is much smaller than the others, scarcely exceeding 

 half the length of the preceding segment, whereas in the other 2 species, this 

 segment is about the same size as the latter. The caudal rami are very 

 slender, linear, nearly twice as long as the anal segment, and extend straight 

 behind. They each carry 6 seta?, 4 apical and 2 lateral. One of the latter 

 is attached close to the tip, the other at about the middle of the outer 

 edge. Both these setae are rather short, and this is also the case with the 

 innermost apical seta. The remaining 3 setas are distinctly ciliated, the 

 middle one being much the largest, attaining nearly Vs of the length of the 

 tail, whereas the outer one is scarcely half as long as the inner. 



No trace of eyes could be detected, and indeed in neither of the 2 

 previously known species have such organs been found to exist. 



The anterior antennae (fig. 3) are much shorter than the cephalic segment, 

 and, on the whole, agree in structure with those in Oncosa, being clothed with 

 slender bristles of considerable length, among which a limited number of very 

 delicate sensory filaments may be discerned. They apparently consist of 7 

 joints, 4 of which belong to the basal part, the other 3 to the terminal part. 

 The joints of the former part are, however, far from being distinctly 

 defined. On the other hand, the lines of demarcation between the 3 joints 

 of the terminal part are fully as distinct as in the genus Onccea, which 

 is not the case in the other 2 species. 



