31 



distinctly 3- articulate and armed in the usual manner, those of 1st pair some- 

 what unequal, in the other pairs of about equal size. Last pair of legs extremely 

 small, and in female quite concealed beneath the dilated matrical part of the 

 body; proximal joint short and broad, and produced outside to a digitiform 

 process tipped with a small bristle; distal joint more or less scale-like, with a 

 small apical bristle and a short spine inside. 



Remarks. This genus was established as early as in the yeart 1847 by 

 Allman, and may be regarded as the type, not only of the present family, but 

 of the whole division Notodelphyoida. It comprises the most perfectly organised 

 forms of that division, and exhibits some unmistakable relations to certain 

 gnathostomous Cyclopoida, in particular the Cyclop in idee. Indeed, the forms 

 included in the present genus may be regarded as Cyclopoids, which by a close 

 adaptation to the particular conditions of life as commensales of Ascidians, have 

 acquired some extraneous characters apparently distinguishing them very essenti- 

 ally from their original ancestors. The genus was in the year 1859 subjected by 

 Thorell to a careful investigation, and its general characters were made out 

 by him in a very satisfactory manner. Thorell distinguished within the genus 

 no less than 7 different species, all of which I have had an opportunity of 

 examining from material collected off the Norwegian coast. These species are 

 very closely related to each others, and as the distinctive characters given by 

 Thorell in the short diagnoses in Latin, preceding the description of each species, 

 appeared to be of a rather trifling kind, the validity of most of them has 

 been questioned by recent authors. On a careful examination I have, however, 

 come to the conclusion, that they all ought to be supported, though their 

 distinction indeed is attended with no small difficulties, at least in the case 

 of preserved specimens. I hope that the descriptions given below, in connection 

 with the figures on the accompaying plates, may render the species more 

 easily recognisable than this has been possible by consulting the work of Thorell. 



1. Notodelphys Allmani, Thorell. 



(PI. XV & XVI) 

 Notodelphys Allmanni, Thorell. Bidrag til kannedomen om Krustaceer som lefva i Arter af 



slagtet Ascidia, p. 31, PI. I, PI. II, 1. 

 Syn: Notodelphys mediterranea, Buchholtz. 



Specific Characters. Female. Body moderately slender, with the anterior 

 division pronouncedly depressed, and nearly twice as long as the posterior. 

 Cephalic segment scarcely longer than the 2 succeeding segments combined, 



