OCR Text |
Show 1890.] OF THE FAMILY BUTHIDCE. 123 Subgenus GROSPHUS, Simon. Grosphus, Simon, Ann. Soc. Ent. Fr. (5) x. p. 378 (1880). Hab. Madagascar. This genus was established upon certain characters observed in the type specimen of Andr. madagascariensis, Gervais. These charcters were (1) a single tooth on the inferior border of the movable digit of the chelicerae, 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 madag ascariensis, and inhabiting the same area, present the normal armature of this segment of the chelicerae, have led me to conclude that the absence of the second tooth is merely an individual variation. But since these species, with madag ascariensis, 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 Rhoptrurus. Inferior border of the movable digit of the chelicerae with one or two teeth. Basal pectinal tooth in $ 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 lsometrus and Parabuthus, so does Grosphus connect Lepreus with Parabuthus. It differs from Lepreus in the armature of the chelicerae 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 m e impossible at present to say. The following are the species I refer to this subgenus :- Cr. madag ascariensis, Gervais (under Androctonus), Arch. Mus. iv. p. 213, pi. xi. figs. 1-3 (1839) ; 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. 1 Buthus limbatus, B. piceits, Pocock, Ann. N. H. (6) iii. p. 316 B. lobidens, id. t. c. p. 461. |