1890.] OF THE FAMILY BUTHID.E. 123 



Subgenus Grosphus, Simon. 



Grosphus, Simon, Ann. Soc. Ent. Fr. (5) x. p. 378 (1880). 



Sab. Madagascar. 



This genus was established upon certain characters observed in 

 the tvpe specimen of Andr. madagascariensis, Gerrais. These 

 charcters were (1) a single tooth on the inferior border of the movable 

 digit of the chelicerse, and (2) the enlargement of the basal pectinal 

 tooth. At the time M. Simon probably was not aware that the 

 latter character is sexual and, consequently, by itself, is not of 

 generic importance. The first character, certainly, if proved to be 

 constant in a number of individuals, would be unquestionably of 

 generic value ; but the fact that this very character has been noticed 

 as an abnormality in Butheolus, and, moreover, that three other 

 species ' obviously very closely allied to madagascariensis, and 

 inhabiting the same area, present the normal armature of this segment 

 of the chelicerse, have led me to conclude that the absence of the 

 second tooth is merely an individual variation. But since these 

 species, with madagascariensis, appear to me to constitute a natural 

 and, at all events, subgenerically distinct group, I have retained the 

 name Grosphus for them and have made the necessary alterations in 

 the definition of the subgenus. 



It may be characterized as follows : — 



Denticles on the digits of the chelae as in Ithoptrurus. Inferior 

 border of the movable digit of the chelicerc© with one or two teeth. 



Basal pectinal tooth in 2 the largest of the series. Tergites 

 with a median keel ; cephalothorax without keels. 



Tail moderate ; not strongly and granularly keeled ; with or 

 without a spine beneath the aculeus. 



As Rhoptrurus appears to connect Isometrus and Parabuthus, so 

 does Grosphus connect Lepreus with Parabuthus. It differs from 

 Lepreus in the armature of the chelicerse and in the disposition of 

 the internal series of teeth on the digits of the chelae, but appears 

 to be allied to it in having an enlarged basal pectinal tooth. Whether 

 or not this last character is a sign of affinity between the two it 

 seems to me impossible at present to say. 



The following are the species I refer to this subgenus :— 



G. madagascariensis, Gervais (under Androctonus), Arch. Mus. 

 iv. p. 213, pi. xi. figs. 1-3 (1S39) ; Simon, Ann. Soc. Ent. Fr. (.5) 

 X. p. 377(1880). 



G. limbatus, Pocock (under Buthus), Ann. Nat. Hist. (6), iii. 

 p. 346(1889). 



G. piceus, id. t. c. p. 349. 



G. lobidens, id. t. c. p. 461. 



All are from Madagascar. 



3 



' Buthus linibatus, B.jjicctis, Pocock, Auu. X. H. (6) iii. p. o46 B. lobidens, 

 id. t. e. p. 4(3 1. 



