Coxal glands of the Arachnids. 237 



Siibfam. Centrurinae. 



Centrurus {?sp.), Arizona. 



Tityns, Panama. 



Centrums margaritakis, Jamaica and Mexico (ale. sp. P). 



2. Fam. Scorpionidae. 



Scorpio mmirus, Biskra, Algeria. 



Biplocentrus scaber, Jamaica. 



OpisthacantJms elatns, Panama. 



3. Fam. Chadidae. 



Euscorpius italicus, Lugano, Italy. 



Ckactas {sp. ?), Colombia. 



4. Fam. Vejovidae. 

 Vejovis flavies, Arizona. 



The lymphatic organ is present and readily found in every 

 specimen from the families Scorpionidae, Chactidae and Vejovidae, but 

 no trace of it has been found in any one of the Buthid specimens 

 from the egg up to the adult. This fact, I think, tends to support 

 the hypothesis that it is a recently acquired organ, since if it had 

 been ancestral and discarded by the Buthids, there surely would 

 have been some evidence of it in the earlier stages of development. 

 If the organ can be regarded as a diverticulum or hernia from the 

 diaphragm, as suggested by Kowalevsky, its origin can be accounted 

 for in a very simple way. 



There appears to be some contradiction here with Kowalevsky's 

 findings, since he describes the organ as occurring in Buthus occi- 

 tanus, but he himself says that he could not find it in the very 

 closely allied Buthid Androctonus, and it seems probable that the 

 specimens sent to him from the South of France were not Buthus, 

 but the equally common Euscorpius flavicauda (Chactid). 



2. Pedipalps. 



The conclusions here arrived at with regard to the coxal glands 

 of the pedipalps are based upon a study of 7 specimens of Tarantula 

 palmata from Colombia, and 4 of Tarantula fuscimana from Panama 

 and Costa Rica. The coxal glands of these two closely allied species 

 of the Tarantulidae {Phrynidae) are precisely alike in every particular 



