Mr. R. Shelford's Studies of the Blattidm. 249 



the type. Kirby (1904) employs the name Pseudomops for 

 all the South American species placed by various authors 

 in the genus Tliyrsoccra, six Oriental species are placed in 

 the genus Thyrsocera and fourteen in the genus Hemithyr- 

 socera. Rehn (1904) also applies Pseudomops to the Neo- 

 tropical species, but sinks Hemithyrsocera as a synonym of 

 Thyrsocera, spectahilis being selected as the type of that 

 genus. An examination of most of the species on which 

 these conclusions are based brings to light the following 

 facts: — i. Thyrsocera spectahilis, Burm., is a Periplanetine, 

 as shown by the valvular character of the last ventral 

 segment of the female and by the wing-structure ; Ellip- 

 sidium speciosibm, Wlk., the type of which is in the Oxford 

 Museum, is closely allied. Dr. A. Brauer, director of the 

 Bei'lin Zoological Museum, has kindly favoured me with a 

 drawing of Burmeister's type and a sketch of the sub- 

 genital lamina of that example, and there can be no, 

 doubt but tliat Thyrsocera, Burm., is a ditypic genus of 

 the sub-fam. Periplanetinas. 



Thyrsocera may be re-described as follows : — 

 Thyrsocera, Burm. 



Autennge incrassated in the basal half and hirsute, the hairs being 

 longer and more dense on eight to ten joints just beyond the middle 

 of the antenna} forming here a conspicuous tuft ; third joint not 

 longer tlian second. Head projecting sliglitly beyond the vertex ; 

 eyes and antennal sockets equally widely separated. Pronotum, 

 smooth, trapezoidal, sides defiexed. Tegmina extending considerably 

 beyond the abdomen with the marginal field broad, the veins in the 

 basal part indistinct, marked by series of punctures. Wings with the 

 basal half of the marginal field coriaceous, both radial and ulnar 

 veins multi-ramose. Front femora with a serried series of short spines 

 on the anterior margin beneath, wdth one or two spines only on the 

 posterior margin, the other femora sparsely armed, all with apical 

 spines on both margins and genicular spines. Tibise with spines in 

 three rows above. Metatarsus equal in length to the remaining 

 joints. Supra-anal lamina quadrate, cucullate with a median carina, 

 its posterior border emarginate ; sub-genital lamina of usual Peri- 

 planetine type. Cerci of moderate length, tlattened and spatulate. 

 Males unknown. 



The two species may be distinguished as follows : — 



Three joints beyond the antennal tuft white. Pronotum broadly 



