91 



Remarks. In the slender and attenuated shape of the body this form 

 bears a general resemblance to some species of the genus Cletodes. It is 

 however at once recognised from them by the peculiar shape of the cephalic 

 segment, as also by the rather different structure of the anterior antennae and 

 of the 1st and last pairs of legs. 



Occurrence. Some few female specimens of this peculiar form were 

 found at Riser in depths ranging from 30 to 60 fathoms, coarse muddy sand. 



Gen. Nannopus, Brady. 



Remarks. Two species only of this genus are as yet known, the one 

 (the type), N. palustris Brady, occurring in brackisk water on the coasts of 

 northern Europe and described in Vol. V, p. 307, the other having been 

 recorded by the present author form the great fresh-water lake Tanganyika in 

 Central Africa, under the name of Ilyophilus perplexus. I am now enabled 

 to add a 3rd very distinct species, which, unlike the other two, is a true 

 marine and deep-water form. 



74. Nannopus abyssi, G. O. Sars, n. sp. 



(PI. XLIII). 



Specific Characters. Female. Body short and stout, gradually tapered 

 behind, with the segments not very sharply marked off from each other and 

 perfectly smooth. Eye absent. Cephalic segment about equalling in length 

 the 3 succeeding segments combined, and evenly vaulted above; rostral pro- 

 jection abruptly deflexed, with the tip obtusely pointed and only provided on 

 each side with a single sensory hair. Urosome scarcely longer than the 

 exposed part of the trunk; genital segment comparatively large and imper- 

 fectly subdivided in the middle; last segment much shorter than the preceding 

 one, with the anal opercle very small. Caudal rami about twice as long as 

 they are broad at the base, and somewhat tapering distally, each ramus armed, 

 inside the 2 juxtaposed bristles of the outer edge, with a short transverse row 

 of small spinules; dorsal seta issuing near the base of the ramus; apical setae 

 comparatively short, the middle one of quite normal appearance. Anterior 

 antennae short and stout, scarcely exceeding half the length of the cephalic 

 segment and, as in the other 2 species, composed of 5 joints clothed with 

 rather strong, for the most part ciliated setae; the first 3 joints successively 

 diminishing in size, the 3rd being rather produced at the end anteriorly, the 



