206 MR. o. THOMAS ON SOME [Mar. 1 7, 



A bronzy black stripe, showing slightly greenish in some lights, 

 covers segments 3-6 above (terminal segments wanting). Wings 

 hyaline, with 1 1 postcubital nervures ; pterostigma pale yellow, very 

 oblique and pointed at the ends, and covering less than one cell. 



Kandy (August 1888). 



Allied to Stenobasis occipitalis, Selys, from New Guinea; but 

 in A. ceylonica the head is concolorous, and consequently there 

 are no postocular spots, a character which I regard as purely arti- 

 ficial. Arehibasis {Stenobasis, Selys) appears to differ from 

 Teinobasis {Telebasis, p., Selys) in the position of the basal post- 

 costal nervure. In Arehibasis it is placed about halfway between 

 the level of the two antecubital nervures, whereas in Teinobasis it is 

 placed close to the level of the second. 



13. Lestes elatxjs. 



Lestes data, Selys, Bull. Acad. Belg. xiii. p. 319 (1862). 

 Pundaloya. 



14. Lestes gracilis (?). 



Lestes gracilis, Selys, Bull. Acad. Belg. xxiii. p. 327 (1862). 



A pair of Lestes in Mr. Green's collection from Pundaloya agree 

 fairly well with De Selys's description of this species, but they present 

 no trace of bluish colouring, and the male has only 9 postcubital 

 nervures on the anterior wings; the female has 12. The genus 

 Lestes is well represented in Ceylon ; and I do not feel justified in 

 describing Mr. Green's specimens as new in the absence of others of 

 the same section from the island. 



I have passed over two other Dragonflies in Mr. Green's collection, 

 allied to Agrionoptera and Ccenagrion respectively, pending the 

 acquisition of a larger series. 



EXPLANATION OF PLATE XX. 



Fig. 1. Orthetrum carnaticum, Fabr., p. 204. 



2. Keurobasis apicalis, sp. n., neuration, p. 204. 



2 a. , anal appendages. 



3. Platysticta greeni, sp. n., p. 204. 



3 a. , anal appendages. 



4. Arehibasis ceylonica, sp. n., p. 205, 



4. On some Antelopes collected in Somali-land by 



Mr. T. W. H. Clarke. By Oldfield Thomas. 



[Eeceived March 17, 1891.] 



(Plates XXI. & XXII.) 



By the kindness of Messrs. Rowland Ward & Co., the well-known 

 taxidermists of Piccadilly, I have been entrusted with the examination 

 of the fine series of Antelope heads and horns recently collected in 

 Somali-land by Mr. T. W. H. Clarke. These Antelopes prove to 



