no. 1104. PARASITIC COPEPODS—CALIGID.E— WILSON. 687 



merit (seven-tenths of it). Genital segment ovate, one-third the width 

 of the carapace, longer than wide, and quite squarely truncated pos- 

 teriorly. There are two pairs of blunt papilla? projecting backward 

 from the posterior portion of the lateral margins of this segment. 

 The abdomen is quadrangular in outline, wider than long; the anal 

 laminae are very long, while the plumose setse which they carry are 

 nearly as long as the entire abdomen. 



Total length 4.5 mm. Length of carapace 2.8 mm.; width of same 

 2.4 mm. ; length of genital segment 0.8 mm. ; length of abdomen 0.4 mm. 



This species closely resembles L. hippogldssi (Kroyer) and L. appen- 

 dieulatus (Kroyer), of the latter of which only the male is known. 

 But in both these species the branches of the furca are bifid and close 

 together, while the general proportions of the body and its parts are 

 also entirety different. 



The National Museum collection includes several lots of this species 

 taken during the voj^age of the United States Bureau of Fisheries 

 steamer Albatross in 1888. They are all from the northern Pacitic, a 

 portion of them on the American side and the rest on the Asiatic 

 coast. From Humboldt Harbor, Shumagin Islands, Alaska, an unnum- 

 bered lot containing twenty females and ten males, no host given. 

 From Loring Harbor, Alaska, an unnumbered lot taken from the cod 

 of that region, Gadus macrocephalus. 



From Chignik Ba}- , Alaska, another unnumbered lot; also from the 

 cod, Gadus macrocephalus. From the Commander (Kommandorski) 

 Islands, Siberia, ten females and one male taken from Pleurogrammus 

 monopterygius (Pallas). From a halibut taken off Alaska in the sum- 

 mer of 1880, an unnumbered lot of ten females. From station No. 

 4212 of the United States Bureau of Fisheries steamer Albatross an 

 unnumbered lot taken from a species of Lepidopsetta. 



No specimens of the Caligus curtus or G. rapax were obtained from 

 these Pacific cod, as it seems practically certain would have been done 

 had those species been found there. 



It would seem, therefore, as if this new species of Lepeophtheirus 

 took the place on the Pacific cod occupied by the two species of Caligus 

 on the Atlantic cod. 



LEPEOPHTHEIRUS BIFURCATUS, new species. 

 Plate XXIII, tigs. 285-293. 



J-'< null, . — Carapace elliptical, distinctly longer than wide, and about 

 one-third longer than the rest of the body. Frontal plates well defined 

 with a shallow incision at the center. 



Posterior sinuses broad, well rounded, and slightly inclined away 

 from the central axis, leaving a median lobe considerably less than 

 half the entire width and projecting well back of the lateral lobes. 

 The latter are broad and well rounded. 



Proc. X. M. vol. xxviii— 04 41 



