NO. I3<;i . /,' /.; 1 Y.S70.V F A MERICAN 8IPII0NAPTERA— BAKER. 881 



the reiiiiiindcr having each but a single row of about 18 bristles. 

 The st(M-nit«\s have singles rows of 8-10 l)nstlos each. Tlic scMcnth 

 teroit(> is miMlially i)r()(lucc(l caudad, so that it extends entirely <)\er 

 the eighth tergite. Antepygidial bristles, 1 on each side, mounted on 

 distinct tul>ercles. 



Labial palpi a1)out ecpialing anterioi' coxa' and apparently six-jointed. 

 In tiie niaxillary palpi joint 8 is longei" than 1, and 2 is longer than 4. 

 Head with a very well-developed frontal notch, a very iiiuisual char- 

 acter for this genus. (lena' with '1 ()])Ii(iue rows of bristles, the upper 

 of 1 smaller, the lower of 8 nuich larger, in normal positions. Vertex 

 with the usual row of bristles on hind margin, the lowest large and 

 long, but the disc with two transverse rows purallel with hind margin, 

 the tirst of about 12, the second of about If! bristles. The armature 

 of hind margin of antennal groove is very distinctive. 



Hind coxa' without miiuite teeth on inner surface. The ])rop<)r- 

 tional lengths of hind tarsal joints are about 20-16-10-5-17. 



The male has the lateral portion of the ninth tergite large and coni- 

 cal in outline and armed at the tip with three stout close-set spines. 

 The upper claspers are long, slender, slightlv enlarged toward the 

 tip and there obliquely truncate backward where it is also arminl with 

 one longer, stouter, and several shorter weaker bristles. 



Abdomen of female very bristly; posteriorly the l)ristles are stout 

 and thick set, far more numerous than figured for huhlsH, the outlines 

 of tenth tergite and hind margin of eighth being obscui'cd by the 

 luimerous bristles. The style is almost perfectly cylindrical, rather 

 stout and armed onh' with one stout spine at tip. 



Length, male, h.b mm.; female, tl nun.; color, very dai'k brown. 



Tt/jM.— Cut. No. BS'.tC, l\S.N.M. 



PULEX ANOMALUS, new species. 

 'Plate X, figs. ]-ti. 



In 1899 I collected at Arboles, in southein Colorado, two specimens 

 of a remarkable tlea on a large gray-brown s})ermo])hile frequent in 

 that region. It is in many respects congeneric with //v'/A///.n. but it 

 possesses a strong pronotal ctenidium of about nine spines. 



The abdominal segments each ])ossess but a single transvers*' row of 

 bristles, eleven or twelve bristles in each row on the tergites, four or 

 six in each on the abdominal sternites. The tergites are' api)arently 

 without mimite teeth. On the thorax the lateral spines are consider- 

 ably the strongest. There are two antepygidial spines of medium si/e, 

 one on each side. 



The head is normal in the female, but in the male is tlatteniHl and 

 thickened on to]) after the manner of (rn>/o/>/i////>/s. The frontal 

 notch is conq)letely al)sent. 'i'he gena possesses but two large heavy 

 spines, one in fi-ont of the medium sized eye. the othei- near lower 



