99 



antennas very imperfectly hinged and composed of only 14 joints. Last pair of 

 legs differing from those in female by the presence on the distal joint of 3 

 additional spines attached to the inner edge. 



Body in both sexes of a whitish colour, with a broad dark purplish, or 

 almost black band across the posterior part of the trunk, occupying the whole 

 of the 2nd, 3rd and 4th segments. Rostrum of a similar colour, and the 

 anterior antennae, the natatory legs, and the ends of the caudal rami also 

 more or less dark in colour. 



Length of adult female amounting to 1.03 mm., of male to 0.73 mm. 



Remarks. This is a very distinct and easily recognisable form. It was 

 at first recorded by Scott as a species of the genus Cydopicera Brady, but was 

 subsequently justly removed from that genus by Giesbrecht, and referred to his 

 new genus Rhynchomyzon. The present species may be regarded as the type of 

 that genus. 



Occurrence. I have only met with this form quite occasionally at Aale- 

 sund and Christiansund, west coast of Norway. The specimens were found in 

 moderate depths among dredged material. 



Distribution. British Isles (Scott), Gulf of Naples (Giesbrecht). 



58. Rhynchomyzon rubrovittatum, G. 0. Sars, n. sp. 



(PL LXII). 



Specific Characters. Female. Anterior division of body less strongly 

 vaulted above than in the preceding species, and, viewed dorsally, of a some- 

 what irregular oblong oval form. Cephalic segment not quite twice as long as 

 the 4 succeeding ones combined, and narrowly rounded in front, epimeral edges 

 of the segment evenly curved. Rostrum very large, falciform, and terminating 

 in an acuminate point. Antepenultimate trunk-segment produced on each side 

 to a prominent acute process pointing obliquely backwards; penultimate segment, 

 as usual, much smaller, with the lateral parts broadly rounded; last segment 

 scarcely broader than the genital segment. Tail exceeding somewhat in length 

 2 / 3 of the anterior division ; genital segment slightly dilated in front and produced 

 on each side to a spiniform, posteriorly pointing process ; the succeeding segments 

 gradually diminishing in size, and, combined, about the length of the genital one. 

 Caudal rami rather produced, exceeding in length the last 2 segments combined, 

 and somewhat divergent, outer edge perfectly smooth and produced at the end 

 to a well-marked dentiform projection, inner edge finely ciliated; apical setse com- 



