1925] Shoemaker, Amphipoda from Gulf of California 41 



a few plumose setae on hind margin. Peraeopod 5 the longest, second joint little 

 expanded, hind margin bearing many plumose setae. The posterior lateral margins 

 of the abdominal segments 1-3 are evenly convex and their lower posterior angles 

 produced into minute points, lower margins slightly convex. Uropods about as in 

 Lembos. Uropod 3 with outer ramus slightly shorter than inner. Telson very little 

 longer than wide, narrow hind margin slightly excavate with each of the blunt lobes 

 bearing a few setae. 



Female. — Side-plates comparatively narrower and deeper than in male. Gnatho- 

 pod 1 with second joint excavate on front margin, lower anterior corner produced into 

 a point, fifth and sixth joints subequal in width, fifth a little over half the length of 

 the sixth and triangular in general outline, sixth witn edges slightly convex and nar- 

 rowing slightly toward the distal end, palm convex, oblique and smooth, dactyl 

 fitting palm and bearing a row of small teeth on the inner edge. Gnathopod 2 much 

 as in the male, fifth and sixth joints subequal in length, palm less oblique and very 

 finely toothed throughout, dactyl fitting palm and bearing a row of small teeth on the 

 inner edge. Peraeopods as in male; the second joints of peraeopods 4 and 5, however, 

 are more densely furnished with plumose setae on their hind margins. 



Length. — c? 9 mm., 9 10 mm. 



The second and third thoracic segments of the male bear on the 

 center of their ventral surfaces a forward-pointing, slightly conical 

 process probably of the same nature as those which have been observed 

 on several fresh-water amphipods by Sars, Smith, Has well, Chilton, 

 Tattersall and others. These processes, the function of which is not 

 known, appear to have been very seldom observed in marine species. 



Hyperiidea 



Vibiliidae 



Vibilia californica Holmes 



Vibilia californica Holmes, 1908, Proc. U. S. National Museum, XXXV, 

 p. 490. 



Guadalupe Island, Gulf of California, March 3, 1911, electric light; 

 1 specimen. Agua Verde Bay, Gulf of California, electric b'ght; 1 speci- 

 men. Carmen Island, Gulf of California, electric light; 8 specimens. 



This species was described by S. J. Holmes from two speci- 

 mens dredged by the Steamer 'Albatross' off Point Loma, Southern 

 California. 



Hyperiidae 

 Hyperia species 

 San Josef Island, Gulf of California, electric light; 1 specimen. 

 Carmen Island, Gulf of California, electric light; 2 specimens. 

 These specimens are all quite young, so that it is hardly possible to 

 identify them specifically. 



