NO. i3f.i. REVISION OF AMERICAN SIPHONAPTERA— BAKER. 417 



CERATOPHYLLUS COLORADENSIS Baker. 

 Plate XXV, ligs. »>-!). 



Thi.s was originally collected with divisxis. It is. however, far 

 larger and differs in many characters which can scarcely be secondary 

 sexual characters, jndoing- from experience with many other species. 

 Further collections of ))oth species are great desiderata. A careful 

 comparison of synopsis and drawings will show the conspicuous 

 differences. 



CERATOPHYLLUS EREMICUS, new species. 



There have ])een in the collection for some time two female spec- 

 imens collected from a nest of Peroiiiy.sevs tvemicus in the foothills of 

 the Santa Rita Mountains, Arizona, by Mr. H. G. Hul)bard. By rea- 

 son of the greatly elongate first joint of hind tarsi this species is closelv 

 related to coloradensix^ but it possesses a number of ver}' distinctive 

 features. 



Upper margin of head a broad, sloping curve from occiput to frontal 

 notch, which is distinct though minute. Lower row of three bristles 

 on gena with the middle bristle ii^carcely half the length of the others, 

 the upper even with, though somewhat removed from, the small some- 

 what oblong e\^e. Superior row also of three bristles, the upper one 

 not near the edge of the antennal groove, the middle one very minute, 

 and the lower much smaller than the upper. Gena below the eye 

 obtusely pointed posteriorly. Antennal groove reaching scarcely two- 

 thirds the depth of the head; the hind margins with a luunber of 

 minute, irregularly placed hairs. Bristles on second joint of antenna^ 

 very small and short, not half the length of the third joint. Disk of 

 vertex back of middle of antennal groore with one large bristle. Hind 

 margin of head with the usual bristles, one large one at each lower 

 angle. 



Pronotum with a row of about twelve bristles on the posterior third 

 and on the hind margin a ctenidium of about eighteen stout spines. 

 Meso- and metanotum each with a row of about ten larger bristles, 

 anterior to which are several illy defined rows of very minute bristles. 

 Metathoracic epiphysis with one larger bristle on the posterior border, 

 two in front of this, and three in front of and above the latter. Me- 

 tanotum and tirst and third al)doniinal tergites each with one small 

 tooth on either side, the second tergite having two on either side. The 

 middle abdominal tergites have each a row of about twelve larger 

 bristles, and anterior to this a row of about the same number of smaller 

 ones. Antepygidial bristles, three on each side, the middle in each 

 gi-oup longest, the inner shortest. Abdominal sternites each with one 

 low of six bristles, though the sixth and seventh show two or four 



