NEW MALLOPHAGA. 435 



dorsal prong is attached by its base to the mentum near 

 the hind margin of the latter. From the posterior border 

 of the mentum a deeply emarginated fold extends back- 

 ward between the two forks, and is attached to the inner 

 edge of the dorsal prong of each. In the young the eraar- 

 gination is much less, the fold being merely roundly con- 

 cave posteriorly. In this stage it is attached for its full 

 length along the median line to the submentum. In each 

 fork the dorsal prong is rather flattened dorsoventrally ; 

 its outer edge is rounded inward proximally and outward 

 distally, while the inner edge presents the same outlines, 

 only in different order, so that the whole is doubly bent, 

 first inwardly and then outwardly. The curvatures, how- 

 ever, are only slight, and the distal one is more marked 

 than the other. The prong is much wider at its base 

 than elsewhere, and tapers off very much distally. It 

 ends by a triangular expansion, having one side of the 

 triangle facing posteriorly and inwardly. At the base is 

 an oval fossa, and in this the outer prong is articulated so 

 as to allow of considerable movement. At the anterior 

 outer corner of each fossa a large strong hair arises and 

 extends outward and backward, being two-thirds or three- 

 fourths the length of the fork. The ventral prong is 

 more cylindrical than the other and tapers but little. It 

 is almost straight, or slightly curved inwardly near the 

 middle. Its base, however, curves dorsally, to be articu- 

 lated with the other piece, as just described. It ends by 

 a bluntly rounded termination which is very slightly ex 

 panded. Its dorsal surface is covered by numerous fine,, 

 closely arranged, rounded ridges. Proximally these lie 

 almost longitudinal, but they gradually become more 

 transverse, so that the terminal ones form an angle of 

 about thirty degrees with a transverse line through their 

 inner ends. The ridges meet each other along the median 



