628 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.39. 



The present genus forms another connecting link between the Cali- 

 ginse and the Euryphorinas. The presence of lunules marks its close 

 affinity with Caligus^ and the preserved material first obtained was 

 referred to that genus. During the past summer, however, there has 

 been an opportunity to study an abundance of living material, and 

 a more careful examination reveals so many characteristics of the 

 EuryphoriniE that it nmst be placed in the latter subfamily. These 

 include among general characters the large size of the copepod, fully 

 twice that of most species of Caligus^ the possession of rudimentary 

 dorsal plates on the fourth (free) segment, a strongly inflated genital 

 segment, and an abdomen with lateral lobes on the basal joint and 

 posterior lobes on the terminal joint. 



In addition, the first legs have a rudimentary endopod which is two- 

 jointed, both rami of the third legs are distinctly three- jointed, and the 

 fourth legs have an enlarged basal joint, and three small terminal 

 joints arranged like those in Glolopotes and not at all like those in 

 Callgus. 



These, with minor differences in the anatomy of the other appendages, 

 will not allow the species to remain among the Caliginge, but it must be 

 placed with other intermediate forms in the Euryphorinas. 



PARALEBION,a new genus. 



General form similar to that of Alehion. First three thoracic seg- 

 ments united with the head; frontal plates poorly defined and without 

 lunules. Free thoracic (fourth) segment narrow and long, with 

 barely the rudiments of a pair of dorsal plates in both sexes. 



Genital segment elongate in the female, with conical lobes at the 

 posterior corners; much shorter and without lobes in the male. 



Abdomen long and narrow; anal laminae large and armed with 

 nonplumose spines. 



Maxillary hooks present; first maxillae single; furca large and double. 



First three pairs of thoracic legs biramose; endopod of first pair 

 rudimentary; exopod of third legs divided differently from those of 

 Caligus and Lepeophtheirus. Egg-cases like those of the Caliginae. 



Type-species. — P. elongafus, new species. 



PARALEBION ELGNGATUS.b new species. 



Female. — Carapace transversely elliptical, a little wider than long, 

 the anterior margin slightly reentrant and without a median sinus, 

 the posterior margin nearly straight. Posterior sinuses inclined out- 

 wards and egg-shaped; median lobe half the entire width, lateral lobes 

 curved inward at the tips until they touch the sides of the median 

 lobe. Grooves separating the areas arranged like the letter H as in 

 the Caliginae, but with certain modifications. The posterior portion 



o Paralebion, from nap&, near, and Alebion. ^ Elongatus, elongate. 



