ANATOMY AND GENERIC CHARACTERS OF SCORPIONS. 381 



should be re-examined, and the really important characters noted and properly drawn. 

 The descriptions and in many cases the figures of authors who have written on Scorpions 

 are, generally speaking, not very intelligible. 



The points which it seems desirable to note in all cases and to record by enlarged 

 drawings are as follows. I take them in what appears to me to be the order of their 

 importance : — 



I. Form of the sternum, i. e. of the dark-coloured chitinized cuticle called meta- 

 sternite. (PL LXXXII. figs. 1 to 7, a.) 

 II. Arrangement of the nerve-ganglia and innervation of the lung-books. (Wood- 

 cut, fig. 2.) 



III. Ornament of the lamella? of the lung-books. (PL LXXXI. figs. 5, 6, 7.) 



IV. Shape of the spiracula. 



(This, like the two preceding characters, is one which has not before been 

 made use of. In Brotheas subnitens (PL LXXX. figs. 9 and 10) the spiracle 

 is circular, a form which has not been previously noticed in Scorpions.) 

 V. Dentition of the chelicerae in one or two rows. This is more variable than 

 Peters seems to have thought. 



The sharply-cutting denticles of these organs in the Tasmanian Telegonus 

 and in Brotheas subnitens (comp. figs. 7, 8, PL LXXXIIL, and figs. 11, 12, 

 PL LXXX.) are alike, and differ from the blunter teeth of most other forms 

 here figured. 

 VI. Dentition of the chelae. (PL LXXXIIL figs. 21, 22, 23, 24.) 



The Scorpionini exhibit fine tubercles, which are disposed mainly in a 

 line parallel with the long axis of each ramus ; the Androctonini have the 

 straight-line arrangement replaced by a series of short curves. 

 VII. Chitinization of the genital operculum, whether in two quite separate plates, 

 as in Brotheas (PL LXXX. fig. 5), or in one imperfectly divided plate. 

 VIII. Proportion of the hand, whether slender, as in Androctonini, or broad, as in 

 Scorpionini. 

 IX. Proportions of the whole tail compared to body, both as to length and breadth. 

 X. Number of lamellae and secondary basal teeth on the pectens. 

 XL Position of the central eyes. 

 XII. Number and position of the lateral eyes. 



XIII. Keeling or smoothness of the joints of the tail. 



XIV. Proportionate length of the segment preceding the sting. 

 XV. Presence of a spine beneath the sting. 



