84 MISC. PUBLICATION 5 0, U. S. DEPT. OF AGRICULTURE 



This genus is nearest Typhloceras Wagner, from which it differs 

 in having the labial palpus composed of eight segments rather than 

 five. The genus includes but one species. 



Paratyphloceras oregonensis Ewing 



(Fig. 9, C) 

 Paratyphloceras oregonensis Ewing, 1940, Wash. Biol. Soc. Proc. 53 : 35. 



Type host.— "Mink." 



Type locality. — Mercer Lake, Oreg. 



Range. — Known only from the type locality. 



This species was based upon a single female, and no further speci- 

 mens have been recorded. At first glance it seems to belong to one 

 of the genera of the Hystrichopsyllinae, but the presence of a frontal 

 tubercle and less than seven spines in the genal comb (fig. 9, C) 

 immediately separate it from the members of that subfamily. 



The Subfamily HYSTRICHOPSYLLINAE Tiraboschi 



Fronto-epicranial groove distinct. Front not greatly reduced, forming at 

 least one-half of anterior margin of head and not dorsal in position. Gena 

 seldom much enlarged and nearly always longest in a horizontal direction. 

 Frontal tubercle and frontal notch absent. Labial palpus with small number 

 of segments. The genal comb may have more than 6 spines. Hind coxae with 

 or without a row or patch of spinelets on inner surface. The abdomen may 

 have 1 or more combs of spines, some of them being composed of short apical 

 spines. 



Included in the subfamily are nine genera, four of which occur in 

 North America. 



Tiraboschi (75, p. 296) in 1904 established the subfamily Hystri- 

 chopsyllinae. The next year Baker (5, p. 136) raised it to the rank 

 of a family. Since then many and diverse genera have been added 

 to the family, hence the necessity for dividing it into subfamilies. 

 Two of the included genera, Ilystrichopsylla Taschenberg and Steno- 

 ponia Jordan and Kothschild, contain the largest known fleas. 



The interpretation of Wagner (86 ', p. 80) concerning the grouping 

 of genera about the genus Hystrichop.sylla is very different from that 

 of the present writers, and, exclusive of Hystrichopsylla itself, no 

 genus is common to both concepts of the subfamily. This is due to a 

 difference of opinion in regard to the significance of the double 

 receptaculum seminis, which is the chief character in Wagner's 

 diagnosis of the subfamily. Inasmuch as the double receptaculum 

 seminis is a sex character, the present writers are unwilling to regard 

 it as of more than generic significance. Even in this capacity it is 

 not always reliable, for it is sometimes abnormally present in species 

 which ordinarily have a single receptaculum seminis. For example, 

 in the United States National Museum collection there is a specimen 

 of Stenoponia americana (Baker) from Microtus pe?insylvanicus at 

 Edgartown, Mass., which possesses a double receptaculum seminis. 



For the genus Stenoponia, Wagner has established a subfamily 

 which includes no other genera, and here again the writers are not 

 in agreement with him. The various characters used to diagnose his 

 subfamily Stenoponiinae are, in the opinion of the writers, of no more 

 than generic significance. 



