66 



part and gradually attenuated behind, with the head comparatively of larger 

 size. Antennae, oral parts, and caudal rami of exactly same structure as in 

 the female. Legs however very different, the 4 anterior pairs exhibiting quite 

 a normal structure, with both rami 3-articulate and armed in the usual manner, 

 being all well adapted for swimming. Last pair of legs very small, knoblike. 



Body of female, in the living state, of a light reddish hue, with the 

 ovarial tubes and the ripe ova of a deep rosy colour. 



Length of adult female attaining 4.10 mm., that of male only 1.20 mm. 



Remarks. The present form cannot be confounded with any of the other 

 known Notodelphyoidas, being at once recognised by its slender vermiform 

 body. The specimen described by Thorell as the male of this species, is 

 quite certainly not a male, but an immature female, in which the 5th pair of 

 legs had not yet attained its full development. The form recorded by Hesse 



* 



under the name of Coeliacola setifera is apparently identical with the present 

 species. 



Occurrence. Several female specimens of this peculiar Copepod have 

 been collected by me at different times and in different places on the Norwegian 

 coast. They were found in the branchial cavity of several kinds of Ascidians. 

 Of males I have only as yet come across a single specimen, and this was 

 not found in Ascidians, but freely among some dredged material obtained at 

 Dr0bak, upper part of the Christiania Fjord. 



Distribution. Coast of Bohuslan (Thorell), British Isles (Brady), coast of 

 France (Hesse, Canu). 



Fam. 5. Botryllophilidae. 



General Characters. Body more or less distinctly segmented, with the 

 anterior division, as a rule, much broader than the posterior. Ripe ova not 

 received in any incubatory cavity, but accumulated to form one or 2 free ovi- 

 sacs appended to the dorsal face of the genital segment. Tail cylindric 

 in form, and composed of a varying number of segments in the different 

 genera. Caudal rami armed at the extremity with strong claw-like spines. 

 Anterior antennae short and compressed, narrowly exerted at the end. Posterior 

 antennae not prehensile. Oral parts well developed, but rather different 

 in structure from those in the preceding families. Posterior maxillipeds 



