NO. 6.] ACCOUNT OF THE SPECIES. 21 



in front. Its lateral faces are perfectly smooth, and almost wholly occupied 

 by the unusually large, but very imperfectly developed eyes, which extend 

 above, so as to meet along the dorsal line. The upper angle of the head 

 forms a very small rostral projection, curved down between the bases of the 

 superior antennae; the lower corners are somewhat more prominent, and 

 between them and the rostral projection, the anterior edges of the head appear 

 very slightly curved. The inferior boundary of the lateral faces is not, as 

 usual, emarginated or incised, but forms on each side an uninterrupted, 

 gently curving line. 



Of the segments of the mesosome, the 1st is considerably longer than 

 the 2nd, which is comparatively very short, both together about equal in 

 length to the cephalon. The succeeding segments gradually increase somewhat 

 both in length and depth, the last, however, being scarcely larger than the 

 penultimate one. The 2 anterior pairs of coxal plates are very small, and 

 partly concealed by the 3rd pair, which are much deeper than the corre- 

 sponding segment, gradually expanded distally, and extended obliquely in front, 

 so as to reach the hind edge of the cephalon (see fig. 1). The 4th pair of 

 coxal plates are still larger, and, as usual, emarginated behind, projecting below 

 the emargination in an obtuse lobe. The 3 posterior pairs of coxal plates 

 are not nearly so deep as the 2 preceding pairs, and are transversally oval in 

 form, slightly decreasing in size posteriorly. 



The epimeral plates of the metasome (see figs. 1 & 3) are of moderate size, 

 the anterior pair being obtusely rounded, whereas the 2 posterior pairs are 

 acutely produced behind, with the inferior edge fringed with delicate bristles. 



The 3 segments of the urosome are well defined, and combined are about 

 half as long as the metasome. The 1st segment exhibits a slight dorsal 

 depression, and the 2nd is very short. In none of the segments could any 

 spines or bristles be detected. 



The eyes (see figs. 1 & 2), as above stated, are of quite enormous 

 size, not only occupying the greater part of the lateral faces of the cephalon, 

 but also extending dorsally, so as to meet in the middle. Their structure, 

 however, is very imperfect, there being no trace of any refracting elements, 

 but only simple, rod-like fibres, imbedded in a dark red pigment. In specimens 

 that have been a long time in strong alcohol, the ocular pigment very soon 

 disappears, as is also often the case in other Lysianassidce. In such 



