Classijication of the Spiders. 317 



(Spavassldse), wliich are well distinguished from the Thorai- 

 soidai by the form of the {oarts of the mouth (especially the tootli- 

 armature of the mandibles), the low clypeus, &c.* Would 

 it not have been better to have written, in the diagnosis of the 

 " Thomisida3," " Die 4 Tracheenschlauche veriistelt (selten 

 einfach)," instead of " Die 4 Tracheenschlauche veriistelt," 

 quite as well as Bertkau, in his diagnosis of the " Lycosida," 

 says, " Augen in 3 (selten in 4) Reihen gestellt " ? Or are 

 the structural characters to be considered invariable only be- 

 cause they are taken from internal organs ? It would, on the 

 contrary, seem that within the province of the Arthropoda in 

 general, the characteristics given by the inner structure are 

 by no means more important or more constant than those taken 

 from the external parts. This has been remarked already by 

 Sundevallf, who has strengthened his opinion with examples 

 taken from the insects. And that also within the class 

 Arachnida, both anatomical and embryological characters may 

 be very different in closely related forms is seen, for instance, 

 from the fact that within a group so compact and so little 

 differentiated as the Scorpions, the first abdominal ganglion 

 is, according to Ray Lankester|, in the family Buthoidje (An-^ 



* Compare Simon, "Rt5vision de la famlUe des SparassidiC," in Acted 

 de la Soi-iete Limieenne de Bordeaux, 1880. 



t " Sveuska Spindlarnes Beskrifniug," loc. ell. p. 192. 



J In a treatise with the title " On the Muscular and Endoskeletal Sys- 

 tems of Lhnulus and Scorpio ; with some Notes on the Anatomy and 

 Generic Characters of Scorpions, byE. Ray Lankester, assisted by W. B, 

 S. Benham and Miss E. J. Beck : Part V. Notes on Certain Points in the 

 Anatomy and Generic Characters of Scorpions, by E. Ray Lankester " 

 (' Transactions of the Zoological Society of London,' xi. part 10, 1885), 

 this author has proposed a new classification of the Scorpions, which cannot 

 fail to cause some surprise among arachnologists. " No writer on Scor- 

 pions," says he, " has given consistently a clear statement or (what is 

 more to be desii-ed) good figures of the really important structural features 

 of the genera, subgenera, and species proposed or recognized by him ; and 

 it is with the object of pointing oat what are the important points in 

 wliich Scorpions may vary that the present remarks are published.'' 

 Among the fifteen points enumerated as important by Prof. Lankester, 

 no less than eleven would, however, seem to have been duly appreciated by 

 his predecessors ; the remaining four are : — ( a) the above-named different 

 disposition of the abdominal ganglia and of the great nerves of these ; 

 (6) the difl'erent sculpturing or ornamentation of the lamellae of the air^ 

 sacs ; {c) the shape of the spiracula, which are oval in " Buscoi-pius" 

 slit-like in '^ Buthus (Heterometrm, Ehr.)," and circular in " Brotheas'' 

 (of the shape of the spiracula in the " Androctonini " nothing is said) ; 

 and {d) the '' chitinization of the genital operculum, wliether in two quite 

 separate plates, as in Brothea^^ or in one imperfectly divided plate.'* 

 Chiefly on the strength of the points («) and (b) Prof. Lankester divides 

 the order of the Scorpions (which according to him form a single family) 

 into two siibfainilies — I. Scorpionini ( = Scorpiouini4-Telegouini, Peters) 

 and II. Androctonini (= Androctonini + Centrurini, Peters). To his 



Ann. & Mag. N. Hist. Ser. 5. Vol. xvii. 22 



