Remarks. In its general appearance this form is rather similar to 

 certain species of the genus Cydopina, and I was indeed at first inclined to refer 

 it to that genus. The closer anatomical examination has, however, proved it to 

 be in reality so different, that in my opinion it ought to be generically separated. 



Occurrence. I have met with this peculiar form in several distant places 

 on the Norwegian coast, for instance at Ris0r and Lillesand on the southern 

 coast, at Christiansund on the western coast, and in the Trondhjem Fjord. In 

 all places it occurred on a muddy bottom, partly covered by decaying algae, the 

 depth ranging from 20 to 40 fathoms. 



Gen. 4. CyelOpetta, G. O. Sars, n. 



Generic Characters. Body somewhat depressed, with the 2 chief divisions 

 less sharply marked off from each other than in the 2 preceding genera. Head 

 confluent with the 1st pedigerous segment, and conspicuously contracted in front. 

 Tail comparatively short. Anterior antennae of inconsiderable length, with the 

 number of articulations reduced. Posterior antennae likewise unusually short and 

 stout, and clothed with strong plumose setae. Mandibles with the palp distinctly 

 biramous, outer ramus well developed, inner uniarticulate. Maxillae and maxilli- 

 peds very small and difficult to examine, though apparently built on the same 

 type as in the other Cyclopinidce. Natatory legs well developed and of normal 

 structure. Last pair of legs consisting each of a single lamellar joint edged 

 with ciliated setae. 



Remarks. This new genus in some respects differs rather conspicuously 

 from the 2 preceding ones, and seems to exhibit a certain approach to the next 

 anomalous genus, Pterinopsyllus, though it is distinguished also from this genus 

 by several well-marked characters. The genus is only founded upon a single 

 species, to be described below. 



8. Cyelopetta diffieilis, G. 0. Sars, n. sp. 



(PI. IX). 



Specific Characters. Female. Body comparatively short and stout, 

 and distinctly depressed, with the anterior division oblong fusiform in outline, 

 greatest width scarcely exceeding half the length, and occurring about in .the 

 middle. Cephalic segment rather large and evenly contracted anteriorly, with 



