122 Dr. M. Laurie on the 



1. The Lung-books. 



The results of an examination of the lung-books of a few 

 forms in addition to those described in my previous paper 

 may be very briefly stated. They all came under two 

 types : — 



(1) Spinous type. 



ScORPiONiDiE : Ischnurus ochropus, Koch ; Hadogenes 

 troglodytes (Pet.) ; Hemiscorpnis lepturus, Pet. 



IURIDJ3 : Anuroctonus phoeodactylus (Wood) ; Broteas 

 Herhsti, Thor. 



BOTHRIURIDJE : Cercophonius squama (Gerv.). 



(2) Reticulate type, 



Butheolus thalassinusj Sim. ; Heterocharmus cinctipes^ Poo. ; 

 Chcerilus variegatus, Sim. 



The reticulate forms are of special interest. Hitherto I 

 have only found this structure in tlie Buthidse, and am inclined 

 to consider it as characteristic of them. Butheolus and Hetero- 

 charmus are both somewhat aberrant forms of this family. 

 Heterocharmus has a pentagonal sternum, and its close ally 

 (if, indeed, the two are distinct genera), Charmus, Karsch, 

 •was placed by its author in the subfamily lurini of the Pan- 

 dinoidge of Thorell. The possession of reticulate lung-book 

 lamellee is strong confirmation of the ac.uracy of their present 

 position. Chcerilus variegatus is also an aberrant form, 

 having among other points of interest circular stigmata. 

 Pocock places it in a subfamily by itself among the luridaj, 

 but its position seems somewhat uncertain, and the lung-books 

 are strong evidence in favour of a relationship to the Buthidge. 



11. Development. 



The terms I have hitherto used to define the two chief 

 types of development will no longer serve, because there are 

 so many variations from the type in each case that to speak 

 of Scorpio and Euscorpius types of development is misleading. 

 The fundamental difference is that while in the one case^ what 

 1 have described as the Eusco7'pius type, the egg early leaves 

 the follicle in which it is formed and passes into the cavity of 

 the ovarian tube, in the other case {Scorpio type) the egg 

 develops in situ, and as the embryo becomes too large for 



