Anatomy and Development of Scorpions. 129 



stages, and the ovary has been seen only in Diplocentrus. 

 The edges of the lung-book lamellae have an arcade structure 

 in Diplocentrus and Neho. 



Subfam. 5. Hemiscobpiini, Pocock. 

 Hemiscorpias. 



Here also only the ovary is known. The lung-book 

 lamelbe are spinous. I leave the subfamily because there is 

 no evidence to justify me in altering it, though Kraepelin 

 places the one genus among the Ischnuriai. 



Bubfara. 6. Urob acini, Pocock. 

 Urodacus, (lodacus) , [loctonus). 



The chelicerge form a channel for the secretions of the 

 appendix, and there are also secreting cells round the top of 

 the diverticulum. The lung-book lamellse are spinous. 



The above observations all agree with Pocock's family 

 Scorpionidge, and consequently tend to support his view as 

 to the importance of the pedal spur as a systematic character. 



The alterations above are comparatively slight, only one 

 new subfamily being constituted. Further knowledge would, 

 however, probably lead to other minor alterations. 



The remaining forms seem all to be apoikogenic. Pocock's 

 luridffi seem to require a great deal of alteration, the other 

 two families remaining almost as they are in his classification. 

 The following is what I would suggest as a provisional 

 arrangement : — 



Fam. II. 



Vejovini, Kraepelin. 



The character I depend on here is the apoikogenic develop- 

 ment combined with the small size and comparative or 

 absolute absence of yolk in the egg. 



Subfam. 1. lusiNi = Iu7-i7ii, Thov.,+ Carahoctonus. 

 lurusj [Uroctonus), Caraboctonus. 



This subfamily is characterized by the arcade structure of 

 the free edges of the lung-book lamellse. I have not seen 

 the ovary of Caraboctonus. 



