ME. H. M. BERNARD ON THE CHEENETIDJ];. 421 



" ram's-horns," presently to be noticed, tlie specimen shown in 

 fig. 11 ought, according to Menge, to be a male. According to 

 Croneberg, the abdominal glands are developed both in the males 

 and the females, though presenting slight differences in the two 

 sexes. 



The coxal glands are blind tubes with the characteristic walls. 

 The ground-substance of the wall often stains very badly, and 

 appears to be perforated by branching pores, which give the 

 whole a spongy appearance. It is doubtful, however, whether 

 this is the true account of its structure. Nuclei are found in 

 the wall, as shown in fig. 13. The epithelium round the com- 

 mencement of the tube is very little differentiated. The aperture, 

 which Sturany * failed altogether to find, is on the posterior face 

 of the coxa of the third leg ; the Chernetidse corresponding in 

 this respect with Scorpio t- The gland runs inward and forward, 

 whereas in Scorpio the gland runs from the aperture inward and 

 backward, owing to the shifting forward of the limbs. 



The duct of the gland is coiled, but the coil it makes is not 

 very complicated. Eig. 14 is a reconstruction of the gland from 

 a series of camera-lucida drawings. The blind end of the tube 

 is practically enveloped by the coil. The whole gland is separated 

 from the alimentary canal by the peritoneal cells, which we have 

 already described as investing the whole of the mid- and hind- 

 guts. 



The Trachece. 



The tracheae open through long slit-like stigmata, from the 

 inner end of which the trunk slopes inward and forward ; both 

 the aperture and the trunk are protected by forked hairs pro- 

 jecting into the cavity. It is not easy to see whether these slit- 

 like stigmata are open furrows, or closed tubes, with an opening 

 only at their inner ends (Croneberg). An examination of the 

 specimen shown in fig. 1, where the cuticle is folded, seems to 

 show that the former description is the correct one. The 

 proximal end of the trunk is somewhat widened, and gives rise to 

 an enormous number of fine tubules. These tubules are intra- 

 cellular. Near their points of origin the protoplasm containing 



* "Die Coxaldriisen der Arachnoideen." Arb. Zool. Inst. Wien, t. ix. 

 1891. 



t " The Coxal Glands of Scorpio;' ^nn. & Mag. N. H., July 1893. 



