AEACHKIDA OP LAKE UEill. 495 



although the tail is more powerful, the crests are very per- 

 ceptibly less strongly granular. This is particularly noticeable 

 ou the inferior median crest of the 2nd and 3rd segments, which 

 in B. afghanus are strongly elevated posteriorly, but are scarcely 

 noticeably so in B, persicus. Similarly, the inferior lateral keels 

 of the 5th segment are much less strongly denticulate, and the 

 posterior lateral prominence is trilobate, not bilobate. 



Pectinal teeth 25-26, S ; 20-21, $ . 



In the palpi the hands are large, smooth and rounded, not 

 crested in either sex, larger in S than $ . I'iogers more strongly 

 lobate in c? ; in both sexes the movable digit is much longer than 

 the hand-back, and slightly exceeds the length of the brachium ; 

 12 rows of teeth, as in afghanus. 



Measurements in millimetres :^ S (type). Total length 49 ; 

 length of carapace 6'5, of tail 31 ; height of 3rd segment 3*9; 

 length of inferior keel 3*8, width 4; width of hand 3'4; length 

 of hand-back 4, of movable digit 6. 



5 . Total length 61, carapace 6"2, tail 34. 



Log. Seir; landing on east side of lake. 



According to Dr. A. Birula, wlio has examined many Trans- 

 caspian Scorpions allied to afghanus and persicus, B. afghanus, 

 Poc, is synonymous with B. thersites, C. Koch *, the latter 

 being but a subspecies of B. eitpeus of C. Koch f. But since 

 the locality of the original thersites is unknown, and the descrip- 

 tion of the specimen or specimens to which Dr. Birula gave that 

 name does not apply to the typical examples of B. afghanus, at 

 all events in the form of the 3rd segment of the tail, I prefer to 

 cite the species or subspecies by the name under which I originally 

 described it. 



Note. — Subjoined is the description of a new species of the genus 

 Buthus from Persia : — 



BUTHUS VESICULATUS, sp. n. (PI. 26. fig. 4.) 



Colour of trunk, chelae, and tail entirely pale yellow. In structural 

 characters, i. e., form of palpi, of cephalothoracic and abdominal keels, 

 closely allied to B. parthorum, Poc, from near Meshed (Tr. Linn, 

 Sue. (2) iii. p. 113, 1889), but at once recognizable by the form of the 

 vesicle and the shortness of the aculeus of the tail. In B. parthorum the 

 vesicle is small and piriform (PI. 26. fig. 8), its -width exceeding its 



* Die Arachn. vi. p. 51, fig. 466 (1839). 

 t Die Arachn. v. p. 127, fig. 419 (1838), 



