154 FROFESSOK. B. RAY LANKESTER. 



In the paper referred to I have given a brief account of the 

 minute structure of these coxal glands in Scorpio and Limulus, 

 and have pointed out the inconclusive nature of the statements 

 made with regard to the structure of the coxal glands of 

 Limulus by Dr. Packard. In Limulus Dr. Packard was 

 unable to find any duct by which the coxal glands open to the 

 exterior, and I have equally failed to find any such duct in 

 Limulus, Scorpio, or Mygale. Although a negative conclusion 

 of the kind must be accepted with some reserve, I am inclined 

 to believe, as the result of a more extended study of these 

 glands by means of complete series of transverse sections of 

 the prosoma in Scorpio, that the coxal glands are devoid of any 

 duct opening either to the exterior of the body or in any other 

 way. They appear to be ductless glands, but possibly further 

 study of them may show that in early life or at some unex- 

 pected point they do possess a duct. 



In minute structure the coxal glands of Scorpio, Mygale, 

 and Limulus present a definite agreement with one another, 

 whilst showing each remarkable peculiarities of structure. 



The nature of these agreements and diff'erences will be best 

 set forth by a description of the structure of each in sequence, 

 and by the comparison of the illustrative figures in Plates XI 

 and XII, which accompany this memoir. 



10. Structure of the coxal glands of Scorpio. 



In transverse sections of the prosoma of Scorpio about the 

 region of the meta-sternum (the pentagonal or triangular cuti- 

 cular sternal plate of Buthus and Androctonus respectively) the 

 coxal glands are seen occupying the position indicated in the 

 accompanying diagram fig. 4 (woodcut). This diagram also 

 serves to show the position of the body t, and sub-neural portion 

 u, of the entosternite and its relation to the coxal glands. 



In such a section it is seen that the cavity of the prosoma is 

 very closely packed with muscles, cseca of the gastric gland (those 

 marked A in the woodcut fig. 2) and the coxal glands s. 



In several complete series of such sections made through the 

 prosoma of specimens of Scorpio Italicus I have failed to find 



