392 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.xxvii. 



on each, several rows of somewhat scattered minute hairs. The meta- 

 thoracic epiphysis has two rows of rather large bristles, about 3 in 

 each row. 



The abdominal tergites each have a transverse row of 14 to Ifi larger 

 bristles and a second row of much smaller ones. There is one ante- 

 pygidial bristle on each side, and these do not e(|ual the tenth tergite. 

 Most of the middle abdominal sternites have each a single transverse 

 row of 6 l)ristles. 



The genitalia are of the general CeratophyUus type and yet are 

 quite unique in detail. The lateral portion of the ninth tergite is 

 lobed above, the lobe as long as wide at base, tip obliquel}" rounded 

 and provided with a bristle. The rounded portion beneath which the 

 upper clasper is attached is provided, as is frequently the case, with 

 two long bristles. The upper claspers are subquadrangular, attached 

 by the lower inner angle, the upper inner angle somewhat produced 

 and provided with three minute hairs, the upper angle broadly 

 rounded, the lower angle considerably swollen and produced and pro- 

 vided with a large long tooth which is distorted near its tip; the hind 

 margin is provided with a bristle at top, beloAv this two short spines, 

 and with two more short spines above the lower tooth. 



Hind coxa3 without minute teeth on inside. Hind femur with Init 

 one minute hair on the side. Spines on apex of second joint of hind 

 tarsi all shorter than the third joint. Hind tarsal joints with lengths 

 in following proportions: 20-15-9-5-10. 



Length, 3 mm. Color, light brown. 



r^i^tf.— Cat. No. (3901, U.S.N.M. 



CERATOPHYLLUS HIRSUTUS Baker. 

 Plate XVII, figs. 1-4. 



The j^rairie-dog flea, not uncommon in Colorado at least, is a very 

 conspicuous species by reason of the great length of the labial palpi 

 and inclosed organs, and the very heavy bristling of the abdomen, 

 though the l)ristling of other parts is normal. Only females are 

 represented in the collection. 



The upper margin of the head slopes very stronglv from base to 

 mouth, the distinct frontal notch being very low down. The e>^e is 

 ver}^ small in proportion to size of head. Just above the eye are a 

 few minute hairs. The gena bears three heavy bristles below, the 

 inner above and slightly in front of eye, the outer on lower margin; 

 above these are two bristles, one larger on lower margin and one small 

 one in center of gena. The gena below the qjq is subtruncate pos- 

 teriorly. The antennal groove is unusually broad for its length, ex- 

 tending to two-thirds the height of the head; the hind margin is 

 provided with numerous small hairs. The numerous bristles on second 

 antennal joint considerably exceed third joint. The usual bristles 



