Coxal glands of the Arachnids. ' 249 



Part II. Tracheate Arachnids and Peripatus. 



Tracheate Arachnids. Solifugae and Plialangids. 



Solifugae. 



Specimens studied: 



Galeodidae. 



Galeodes arabs, Biskra, Algeria. 

 Galeodes (sp.?), Biskra, Algeria. 

 Paragcdeodes barbarus, Biskra, Algeria. 

 Paragaleodes scalaris, Biskra, Algeria. 



Solpugidae. 



Solpuginae. Solpuga flavescens, Biskra, Algeria. 

 Doesinae sp ?, Colombia. 

 Boesinae: Ammotrecha, Texas (ale. sp. M.}. 

 Eremobatinae \ Eremobaies, Texas (ale. sp. M.). 



In the description of the coxal gland of the solifugae we shall 

 find so many new and remarkable features, that the inferences drawn 

 may very likely be erroneous in some respects. But in order to avoid, 

 as far as possible constant repetition of "I think" or "I believe", 

 I shall treat the subject dogmatically and appear to take it for 

 granted that my views are correct. 



The coxal gland lies loosely in the hemocoele; the loops and 

 coils of its tubules extending posteriorly as far as the sixth append- 

 age. The main portion of the gland lies between the second and 

 third appendages and from this point a long narrow tubule runs 

 anteriorly with an outlet on the second appendage. The more 

 detailed description of the gland given below applies to Paragaleodes. 

 Variations from the type of Paragaleodes in other genera will be 

 commented upon later. 



Beginning with the saccule [S) which lies in the main portion 

 of the gland we find thas it hat undergone considerable modification. 

 Since the solifugae, being tracheate animals, have no system of 

 blood vessels outside of the long narrow heart {H\ there is no means 

 of carrying blood directly to the gland as in the pulmonate scorpions, 

 pedipalps and spiders. To remedy this defect, the saccule appears 

 to have been developed into a pumping organ designed to force fluid 

 from the hemocoele into the coxal gland. All around the periphery 

 of the saccule are attached bands of finely striated muscle fibres 

 {MS) which radiate out on all sides (photo 33, 34, 34 a, 34 b) and 



17* 



