REVISION OF STREPSIPTERA PIERCE. 171 



The generic description will have to be drawn from the specific 

 description which follows. The ventral surface of the male is ap- 

 pressed to the dorsum of the host. 



i. COLACINA INSIDIATOR Westwood (1877). 



Host. — Epora subtilis Walker (1857), a fulgorid insect, from Sara- 

 wak, Borneo (pi. 15, fig. 7). , 



Male imparium. — Cephalotheca subquadrate; eye covers at sides, 

 large and somewhat lunate; antennal analogues in form of two 

 rounded spaces, adjacent to eyes and distant from each other by 

 over their diameter, partially covered with minute granules; anten- 

 nal analogues connected by transverse impression; two small trans- 

 verse pieces below antennal analogues represent the mandibular 

 analogues, while the two small swollen spaces which follow these indi- 

 cate the maxillary analogues. 



GEOGRAPHICAL DISTRIBUTION OF THE STREPSIPTERA. 



This subject has been somewhat difficult to handle owing to the 

 fact that onty a little over a hundred species are known, but yet 

 some satisfaction has been obtained by studying the records of 

 insects parasitized, from the geographical standpoint. It is found 

 that there are fifty genera of insects in four orders, and fourteen 

 families, which are known to be attacked by the Strepsiptera, from 

 only 25 of which genera have specimens of parasites been described. 

 In the 50 genera of hosts, 238 species are known to be parasitized, 

 and it is first on the basis of these host insects that the following 

 discussion is founded. 



As a basis for the study of zoogeography there are two excellent 

 works, one by Wallace (1876) and the other by Heilprin (1886), each 

 of which contains a map of the zoogeographic regions of the world. 

 The regions defined by Wallace are accepted by the writer as best 

 adapted to show the distribution of the Strepsiptera. It is, however, 

 well to first draw a few conclusions from Heilprin's standpoint. 



According to the latter author the Strepsiptera as now known 

 would be classed as primarily Holarctic; that is, native to North 

 America and Eurasia, north of the Himalayas. They are entirely 

 absent or unknown from Heilprin's first division of this realm, which 

 extends through Canada, northern Europe, and Siberia. This would 

 therefore define them as belonging only to the temperate and trop- 

 ical regions. 



According to Wallace there are six primary realms which he con- 

 veniently divides into four regions each. His Nearctic realm com- 

 prises all of North America, except a greater part of Mexico. The 

 Palsearctic realm includes Eurasia, except Arabia south of the 



