370 MR. K. S. BAGNALL : CONTRIBrTION TOWARDS A 



I have attempted on PL 52. figs. 5 a & 5 h, to figure the ventral side o£ 

 the ninth abdominal segment o£ the male Dicaiotlirips IcevicolUs, and believe 

 that upon examination of an extensive series the genital characters in the 

 male (and probably in the female also) will prove to be o£ some taxonomical 

 importance. 



I have also endeavoured (PI. 53. fig. 16) to delineate the basal part of the 

 fore-wino- in Dicer atothrips armatiis, drawing particular attention to a light 

 pi\tch that does not appear to be so strongly membranous as the surrounding 

 parts, and is also protected by two bristles. I have thought that this may 

 probably be a sense-area, and believe that it has not before been noted. 



Genus DiCAiOTHKiPS, Bufa, 1909. 

 Dicaiotlirips, Buffa, ' Redia,' v. fasc. 2, p. 169 (March 1st, 1909). 

 This genus was erected recently by Prof. BufFa and is a ditficult one to 

 diagnose with satisfaction, though there can be no doubt that the genus is a 

 good one and quite distinct from Idolotlirips. The species are, as a rule, 

 larger and more massively built than in Idolotliri'ps -, the cheeks of the head, 

 and the fore-legs also (which latter are often considerably enlarged in the 

 male), are very profusely set with spines ; the fore-tarsal tooth is very large 

 in the male, and scarcely noticeable in the female, whilst in the first-named 

 sex the abdomen is exceptionally long and narrow, and the segments in most 

 species are very much elongated. In the majority of species the male is 

 without post-ocular spines ; but these are to be foimd in the female, which 

 sex, so far as may be judged, is always more sparsely set with spines both 

 on the lateral margins of the head and on the fore-legs, and has the abdomen 

 broader and shorter than in the male, and the tube also decidedly stouter. 

 The strong hook-Hke spine at the apex of each fore-femur without, pointed 

 out by Bufia, is apparently not a characteristic of this genus, nor common to 

 all the species. I cannot distinguish it in any of my Neotropical material, 

 and have only observed it in two undescribed species of Dicaiotlirips, one 

 from the Malay Archipelago and the other from North Africa. This 

 character, too, is not confined to this genus ; it is seen in two or three 

 species of Idolotlirips, whilst I have a specimen of an undescribed species, 

 belonging to a genus far removed from these last-named genera, which has 

 these spines very strongly developed. 



The type of the genus is undoubtedly Idolotlirips Sclwtti (Heeger) Uzel *, 

 described from Brazil, to which species Buffa erroneously refers my 

 Idolotlirips foveicollis, and at the same time ascribes a Malayan form to the 

 same species. Both D. Sclwtti and Buffa's Malayan form have the third and 

 fourth antennal joints subequal, which character alone at once separates 



* Heeger, Sitzungsb. d. Akad. d. Wiss., Vienna, viii. p. 139, pi. 23 (1852) ; and Uzel,. 

 Monographie der Ordnung Tbysanoptera, Koniggratz, p. 266 (1895). 



