288 



myself in a single place near Christiania. It occurred here rather plentifully in 

 a depth of about 10 fathoms, on a muddy bottom covered with decaying algse. 

 On revisiting this place, I found the bottom quite altered and almost devoid of 

 animal life ; nor did I succeed in finding this form in any neighbouring place. A 

 single female specimen taken recently at Ris0r, south coast of Norway, has how- 

 ever enabled me to subject the species to a renewed examination. Out of Nor- 

 way this form has not been recorded. 



Gen. 59. OrthOpSyllUS, Brady, 1873. 



Syn: Lilljeborgia, Glaus (not Sp. Bate). 



Generic Characters. Body elongated, sub-cylindric in form, and almost 

 straight, with the segments sharply marked off from each other and coarsely denti- 

 culated behind. Rostral projection very prominent. Caudal rami comparatively 

 short and thick. Anterior antennae with the number of joints much reduced, ter- 

 minal part (in female) consisting of only a single joint; those of male strongly 

 hinged. Posterior antenna} with the outer ramus distinctly defined and resembling 

 in structure that in Laophonte. Mandibles well developed, with the palp imper- 

 fectly biarticulate. Maxillae and maxillipeds of normal structure. 1st pair of legs 

 differing conspicuously from the succeeding pairs, both rami having the apical 

 appendages remarkably dilated in their proximal part, inner ramus exceeding in 

 length the outer, and biarticulate. The 3 succeeding pairs of legs comparatively 

 short, with no natatory setae on the outer ramus, inner ramus small, biarticulate, 

 that of 3rd pair conspicuously transformed in the male. Last pair of legs with 

 both joints produced in lamellar setiferous lappets. Ovisac single. 



Remarks. This genus was established as early as the year 1860 by Glaus, 

 to include a species found by him in the Mediterranean, at Nice. As however 

 the generic name Lilljeborgia proposed by that author had been previously given 

 by Sp. Bate to an Amphipod, Prof. Brady substituted for it in the year 1873 

 that of Orthopsyllus. He subsequently withdrew this name, believing that Claus's 

 species was referable to the genus Cletodes established by him in the preceding year. 

 I think however that the genus Orthopsyllus ought to be retained for Claus's 

 species, because this form differs very materially in several characters both from 

 the species of Cletodes and from those of the other genera included in the present 

 family. We do not at present know more than a single species, to be described below. 



