192 



Dr. M. Laurie on the 



We have thus three types of structure for the lamella, 

 which we may term the spinous, arcade, and reticulate forms. 



The spinous type occurs in IScorpio, Ileterometrus, Opisth- 

 ophthahniiSj Falamnceus, Optsthocentrus, Bormurus, and 

 Urodacus among the Scorpionida3 ; in i'Scorpiops, Vejovis, 

 Hadrurus, and Bruteochactas among the lurida3 ; and in the 

 only member of the Bothriuridse which I have seen, namely 

 Bothriurus. From its wide range this type of lamella is 

 probably the most primitive. 



The arcade type occurs in Diplocentrus and Neho among 

 the Scorpionidae, and in lurua, Caraboctonus, and Euscorpius 

 among the lurid^. 



The reticulate type occurs in Buthus, Parabuthus, Uro- 

 jihctes, and Centrums, all belonging to the Buthid^. 



The morphological value of the lamellai is probably less 

 than that of the development. 



The following table summarizes the two sets of facts and 

 gives a list of the species I have examined : — 



Development. Lung-books. 



Scorpio fulvipes (C. Koch) Scorpio type. Spinou.s. 



Heterometrus, sp j> » » 



Opisthophthahms capensis (Herbst) .... „ „ „ 



I'alamnfeus Thorellii (Poc.) ;, ;, » 



Opisthocentrus mudayascariensis (Kraep.) „ „ „ 



Opisthocentrus validus (Thor.) ? „ 



Mormurus australasics (Fabr.) Scorpio type. „ 



Urodacus nov(e-hoUundice (Pet.) ? „ 



Scorpiops Hardwickii (Gerv.) ? „ 



Vejovis, sp. ined Euscorpius type. „ 



Hadrurus hirsutus (Wood) „ j, „ 



Broteochactas delicatus (Karsch) „ „ „ 



Bothriurus bonariensis (Koch) „ „ „ 



Biplocentrus Whitd (Gerv.) ? Arcade. 



Nebojiavipes (Sim.) ? i, 



lurus Lvfoureius (Brulle) ? „ 



Caraboctonus Keyserlingii (Poc.) ? „ 



Euscorpius italicus (Herbst) Euscorpius 13 pe. ,, 



Buthus niyrolineatus (Dufour) „ „ Reticulate. 



Parabuthus capensis (Gerv.) „ „ „ 



Uroplectes triangulifer (Thor.) ........ ,, „ „ 



Centrurus gracilis (Latr.) „ „ , 



The number of forms examined is far too small to base 

 deductions on with any certainty, and to classify on the 

 ground of these two structures alone would be almost certain 

 to lead to a wrong conclusion. The results seem, however, 

 to suggest the following rearrangement : — 



