NO. 1788. NORTH AMERICAN ERGASILID.^— WILSON. 365 



the latter are two or three times as wide as long, and both rami are 

 armed with large and strongly flattened plumose setae. The second, 

 third, and fourth legs have three-jointed rami, the endopods wider 

 and longer than the exopods, the spines and setae arranged as follows: 

 Second exopod, I-O; I-l; III-5: endopod, 0-0; 0-2; 11-2: third 

 exopod, I-O; I-l; III-6: endopod, 0-1; 0-2; III-2: fourth exopod, 

 I-O; I-O; 1-5: endopod, 0-1; 0-1; II-l. 



The claws are large and toothed along their posterior margin; the 

 fifth legs are two-jointed, the terminal joint much larger than the 

 basal, spatulate in form and tipped with four spines of unequal 

 length; there is also a short spine on the anterior border of the 

 basal joint (fig. 145). 



Color, a light yellowish cartilage gray, inclining to brown on the 

 cephalo thorax. 



Total length, 2.4 mm. Cephalothorax, 1 mm. long, 1.7 mm. wide. 

 Length of second, third, and fourth segments, 0.5 mm. Width of 

 genital segment, 0.4 mm. Length of egg-strings, 1.6 mm. 



{ardeolse, from the name of the host, Belone ardeola Kroyer, which 

 was probably Tylosaurus marinus, the silver gar.) 



There is a single female of this species taken from the gills of the 

 Little Garibaldi, Hy^syyoys ruhicundus, at La Jolla, California, by Dr. 

 J. C. McClendon, and is numbered 38597, U.S.N.M. When the pres- 

 ent author endeavored to locate this specimen among the described 

 species of Bomolochus, it was found to possess difl^erences which 

 could not consistently be included in the same genus. Accordingly 

 a new genus was constructed for this and the species mentioned on 

 p. 361. In the paper dealing with Doctor McClendon's fine lot of 

 specimens nothing but the diagnosis of the new genus was given. '^ 

 In the present paper Kroyer's species, ardeolse, which was taken as 

 the genus type, has been redescribed and figured. This, with the 

 description and figures of the new species, sxtiger, will fix the genus 

 definitely. It is worthy of note that Kroyer's type of the species, 

 ardeolse,, was taken from the gills of a fish captured at New Orleans, 

 and is hence North American. 



Genus BOMOLOCHUS Nordmann. 



Female. — Body with a general Cyclops shape, but usually with a 

 widened cephalothorax and a narrowed abdomen. First thorax seg- 

 ment fused with the head, the others free and diminishing regularly 

 in size; genital segment enlarged but little; abdomen narrow and 

 tapering. First antennae six-jointed, the three basal joints fused 

 together, enlarged, flattened, bent at a right angle near the base, and 

 fringed with a dense row of plumose setae, with a few tactile hairs 



oProc. U. S. Nat. Mus., vol. 35, p. 433. 



