126 
E. S. BAGNALL 
the palpi, chaetotaxy, stigmata, and the ninth and eleventh abdominal 
segments. 
It would seem that the discovery of this minute creature may 
considerably modify our ideas as regards the systematic position of the 
Order Thysanoptera, and perhaps help us to more accurately recognize 
to what other orders of Insects the Thrifts are most nearly related. 
In the following diagnosis of the genus, the characters which may 
be reasonably considered as of more than generic value are italicized, 
being discussed in their relation to the known Tubulifera towards the 
conclusion of this paper. 
Order THYSANOPTERA. 
Suborder TUBULIFERA Haljday. 
Family Urothripidae mihi. 
Genus Urothrips nov. 
Form depressed. Head longer than broad, and one-half (0*5) as 
long again as the prothorax. Eyes small ; ocelli absent. Antennae seven- 
jointed, slightly longer than head and set below the vertex, with second 
joint cyathiform, strongly constricted at base ; third subglobose, and 
similarly constricted into a stem at base; fourth and fifth joints sub¬ 
quadrate, and apparently depressed; sixth elongate, depressed, linear, 
and slightly constricted at base; and the apical joint narrower and 
tapered to tip. Mouth-cone shorter than its breadth at base, scarcely 
reaching one-half (0*5) way across prosternum. Maxillary and labial 
palpi each composed of a single joint. 
Fore-tarsus in both sexes apparently without a tooth. Wings absent. 
Posterior pair of coxae most widely separated. 
Abdominal segments one to eight strongly transverse, and segments 
three to eight armed with a strong s*pine at each posterior angle. Ninth 
abdominal segment elongate, much longer than any of the preceding. 
Terminal hairs of tube extremely long, whip-like in the one sex and 
simple in the other. Bristles and hairs, found on the antennae, head , 
thorax, legs, and abdomen of known Tubulifera, absent or obsolete. 
Eleven pairs of stigmata present. 
