238 • B. H. Buxton, 



SO that a description of one serves equally well for the other 

 species. 



I have not been able to examine examples of the TJwJyphonidae 

 with the exception of a single specimen of Mastigoproctus giganteus 

 (ale. sp. P.) which was in such a bad state of preservation that 

 little could be made out of its details but so far as could be judged, 

 its coxal glands do not differ in general arrangement from those of 

 Tarantula. 



Laukie found an outlet on the third appendage in Tlielijplionus 

 and BoRNER remarks that in the pedipalps the coxal gland is 

 extensive with an outlet on the third appendage; well marked in 

 Tlielyphonus but not so clear in the Tarantulidae. 



The chief works on the development of the Pedipalps are those 

 of Sophie Pereyeslavzewa (1901), Gough (1905) and Schimkevitch 

 (1906). The two former observed in early stages the rudiment of 

 a second gland with indications of a lost outlet on the fourth appen- 

 dage, but the rudiment soon disappears and in the young pedipalp is 

 no longer traceable. 



Borner (1906), in: Zoologica, describes the coxal glands of the 

 pedipalps at some length, but makes no mention of the saccule or 

 collecting tubule, and I cannot find in the literature that they have 

 been observed by any one who has recognised them as a part of the 

 glandular structure, although Pereyeslavzewa figures the saccule 

 in the embryo very clearly, but, mistaking its significance, calls it 

 an "agglomeration of connective tissue", forming tubules which will 

 give rise to additional coxal tubules. There is no evidence in her 

 description or figures that she found the collecting tubule, and since 

 the labyrinth consists of a single coiled tube it seems unlikely that 

 new tubules can be formed and added to it. 



Schimkevitch finds in the young larva a communication with 

 the coelom, but in older stages the communication is lost, although 

 he notes the presence of "stroma cells" which he thinks may 

 correspond to the medullary portion of the scorpion's gland, but the 

 stroma cells lie outside the gland. The "stroma cells" can un- 

 doubtedly be referred to the saccule, but he missed the connecting 

 link between it and the labyrinth. 



In Tarantula, the coxal glands are not compact as in the 

 scorpion, but elongated, stretching posteriorly from opposite the third 

 appendage to a point between the fifth and sixth appendages; the 



