416 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.xxvii. 



Iiri.stles. The metathoracic epiphysis has one bristle at th(^ posterior 

 angle and two others in front of this; still anterior to the latter and 

 somewhat above occur tliree more. Hind margins of metanotum and 

 first and second abdominal tergites each with two small teeth on either 

 side; the third tergite has one on either side. The middle abdominal 

 tergites each with about twenty larger bristles in the posterior row, 

 fewer smaller ones in the anterior row. But one long antepygidial 

 bristle occurs on either side, the others being aborted. Lateral por- 

 tions of eighth segment with numerous bristles in two thick-set lots 

 near the hind margin, the upper lot of about sixteen smaller bristles, 

 the lower lot of al)out twenty larger, longer ones. 



Lateral portion of ninth tergite very large, the lobe very large, 

 scarcely narrow^ed toward tip, and extending as far dorsad as do the 

 claspers. The two bristles over the insertion of the claspers are rather 

 far up on the margin and somewhat separated. The upper claspers 

 are long and narrow; inner margin nearh' straight, the outer roimded 

 and with four bristles. Above, the claspers are squarely truncate 

 across the tip and obliquely so toward the hind margin. 



Hind coxa without minute teeth inside. The hind femur has a 

 longitudinal row of about ten small hairs on side. First tarsal joint 

 with five groups of spines on either side. Spines on apex of second 

 joint of hind tarsi longer than joints ii and iii together. Spines on 

 fifth tarsal joint arranged after the normal Ceratophyllus manner. 

 Lengths of joints of hind tarsi in the proportions 1.5-10.5-6-5-6.5. 



Length, 2.5 mm. Color, pale brown, darker dorsally. 



Type.— Cat. No. 6919, U.S.N.M. 



CERATOPHYLLUS IGNOTUS Baker. 

 Plate XXI, figH. l-(). 



The American mole flea was originally described from specimens 

 taken in Iowa, Colorado, and Idaho, on Geomys hursariuK and Thoino- 

 mys talpoides.^ under two names. The eyes are rudimentary. A 

 certain portion of the material with eyes fairly distinct was placed in 

 Pulex ignotus. Later, additional material, \vith the eyes almost 

 entirely wanting pigment, was described as Typhlopsylla amerlcana. 

 The former name takes precedence. This but illustrates the impossi- 

 bilit}" of using the comparative development of the eye as a primary 

 generic character. 



CERATOPHYLLUS DIVISUS Baker. 



Plate XXI, ligs. 7-10. 



This was originally described from specimens collected by Professor 

 Bruner on Fremont's Chickaree, in Colorado, as Pulex longispinus., 

 which name had, however, been previousl}^ used by Wagner. 



