364 Mv. K. I. Pocock on 



LI. — A ConlribiiHon to the Systematics of Scorpions. 

 By R. I. Pocock. 



I. — Some Corrections in Nomenclature. 



The genus Ischnurus was first published in 1837 in ' Uebersicht 

 des Araclniidensyst./ pt. 1, p. 37, and based upon the species 

 described as I. complanatus, the only species cited under it. 

 /. complanatus, therefore, is the type of Ischnurus ; and since 

 complanatus is congeneric with the type species of Hormurus, 

 that genus falls as a synonym of Ischnurus. 



In his monograph on Scorpions (Das Tierr., Scorpiones, 

 p. 153, 1899) Kraepelin falls into the error of dating 7.9c//m«- 

 rus from 1838, when Koch described under it three species — 

 namely, /. ocliropus, I. austral asm, and /. complanatus ; and 

 since Thorell had eliminated the last two under Hormurus, 

 Kraepelin assigned the remaining species ochropus to Ischnu- 

 rus. This method of dealing was based upon the mistake in 

 the date of publication of Ischnurus. The latter must take 

 complanatus and australasice, leaving ochropus available for 

 the name Chiromachus, which I proposed for it in 1893 (Ann. 

 & Mag. Nat. Hist. (6) xii. p. 320). 



These conclusions may be briefly tabulated as follows : — 



1. Ischnurus, C. L. Koch, Uebers. Arachnidensyst. i. p. 37, 



pi. vi. fig. 69 (1837) (type complanatus). 



Syn. Sistjphus, id. ib. on pi. vi. fig. 69 (errore for Ischnurus). 



Ischnurus (in part only), C. L. Koch, 1838. 



Hormurus, Thorell, Ann. & Mag. Nat. Hist. (4) xvii. p. 14 (1876) 

 (type H. caudicula, L. Koch). 

 Not syu. Ischnurus, Thorell, Karsch, Pocock, and Kraepelin. 



2. Chiromachus, Pocock, Ann. &, Mag. Nat. Hist. (G) xii. 



p. 320 (1893) (type ochropus, C. Koch). 



Svn. Ischmirus, C. Koch, Die Arachn. iv. p. 69 (18^8) (in part.) ; Kraep. 



Jahrb. Hamb. Wis.'^. Anst. xi. p. 130 (1894); id. Das Tierr., 



Scorp. &c. p. 153 (1899). 

 Not syn. Ischnurus, 0. Koch, 1837. 



The name Centrurus, which, since 1876, has been applied 

 ])v common consent to a well-known American genus of 

 Buthidse, was originally projected into literature in 1828 by 

 Hcmprich and Ehrcnberg as a nomennuclum, no species being 

 cited as referable to it (Symb. Phys., Scorpioncs, 1828 ; Verb, 

 nat. Fr. Berlin, 1829, p. 350; Perussac, Bull. Sci. Nat. xviii. 

 p. 304, 1829). It is true that Ehrenberg appears to have 



