164 Proceedni(/s of (he Biological Societj/ of Wasld'iiglon. 
liundredth in widtli. It i.s poli.«lied and sliiuijijf, and of a blackish [)urple 
I iiiiteniicC wliich arc rather lonjjertliaii the liead ajid composed 
of eifjht nearly ecpial jcmits, liave the third joint of a white color. Th<‘ 
abdomen is concave on its niiperside, and is furnished with a conical tnlx' 
at its tip which has a tew bristles iirojecting from its apex. The wings 
when folded are linear, silvery white, and as hmg as the abdomen ; they 
aie pressed clo.sely n])on the back, spreading asunder at their bases, and 
ajipear like an elongated whiti* ^ -shajied mark, \dewed from aliove, tlu* 
head IS of a square form, longer than wid(‘. The first segment of tin* 
thorax is w'ell separated from the second, is broadest at its base, and 
gradually tapers to its anterior end, where it is as wide as the head. Tlu' 
lollowing segment is the hmadest |)art of the body and square, with its 
length and breadth ei^nal. 
Acanthothrips albivittatus Hood. 
1908. Acanthothrips albivittatus lioo(\, Bull. III. State Lab. Xat. Mist., 
vol. AMU, art. TI. p. ;574. 
J912. H[oplothrips, lajisns] albivittatus Ibxui, Can. Lid., vol. XL1\', p. 
I4M, footnote. 
Since its de.scription in 1908 from one femak* taken at Bloomington, 
Illinois, this species has come to hand from the following localities: Car- 
liondale, Illinois, October 10, 1908, L. M. Smith, 1 female from liranch of 
oak; Makanda, Ill., Sejit. 25, 1908, L. AI. Smith, 1 female “found on 
wrist while examining apple leaves” ; Washington, 1). C., June 15-21. 
1913, .1. R. Malloch and .1. I). Hood, 3 females and 2 males reared from 
nymjihs taken June 10 on trunk of dying red oak tree*. 
The male differs from the female in so few' particulars that an addi¬ 
tional description of that sex is unnecessary. 'Fhe black antemue and 
wbih' dorso-lateral strijies are distinctive. 
Cenns Dichsetothrips nov. 
idvo, two; xa/r??, bristle; 0pt\f/, a wood worm.) 
Head subrc'ctanguiar, mnch longer than broad, more than twice as 
long as median dorsal length of pronotum; vertex not produced; cheeks 
smooth, s])arsel 3 ' spinose; ixjstocnlar bristles long, pointed; postocellar 
bristles exceedingly long, nearly as prominent as tbe postocniars. Antenme 
eight-segmented; segments 4-() without ventral prolongations at a]>ex ; 
segment 4 longe.st. Eyes small, about one-fourth as long as head! 
Anterior ocellus directed forward. Alouth cone not as long as wide, 
semicircular at apex, slightly surjiassing middle of prosternum. Bro- 
thorax more than three times as wide across cox;e as jnedian length of 
dorsum ; posteriin- margin nearly straight; anterior margin almos^semi- 
circularly emarginate, consiucuously thickened; anterior marginal and 
anterior angular bristles minute, others well developed. Fore tarsi 
strongly armed. AVings broad, slightly expanded apically. Abdomen 
broad and heavy; tube large and stout, about as long as head. 
Ti/pe : Diche'etothrips brevicollis sp. nov. 
The close relationship existing between this genus and Diceratothrips 
Bagnall is party responsible for the similarity of the two names. In each 
