42 



CARL BOVALLIUS, THE OXYCEPHALIDS. 



Fig. 83. Cutaneous gland 

 in the margin of the 

 first epimeral of Xi- 

 phocephalus Whitei. 



consisting of only one cell, with a short, narrow duct opening into a small 

 circular hole in the surface of the integument (fig. 83), which hole is usually 

 guarded by one or more small simple hairs ; or they are composed of many 

 cells, and packed into thick masses round a central lumen from which a com- 

 mon duct runs to the outlet. The outlet is often placed, as mentioned above, 

 at the base of the dactylus (fig. 84), more seldom at its apex (fig. 65), often in 

 semicircu lar incisions at the upper end of the rami of the uropoda, or as 

 in Xiphocephalus -- at the apex of the telson and of the rami of the uro- 

 poda (fig. 81 and 82). Usually the 

 glands of the legs are concen- 

 trated in the femur, and only a 

 few and scattered glandular cells 

 are to be seen within the follo- 

 wing joints, often tying round or 

 close to the duct which runs from 

 the chief mass of glands in the 

 femur to the base of the dac- 

 tylus (fig. 84); but in the fema- 

 les of the three species of Xi- 

 phocephalus which I have exa- 

 mined, the tibia and carpus of 

 the third and fourth pairs of 

 perseopoda, as well as the same 

 joints of the fifth and sixth pairs 



Fiq. 85. The tibia of the ' , n n4 ~J ^J 



are sometimes inflated, and 



fourth pair of peraeo- f 



poda of Xiphocepha- almost egg-shaped, owing to a 

 lus Whitei. . strongly developed glandular 



mass surrounding the axis of the joint for the whole of its length 

 (fig. 85). The development of these powerful glands in the tibia and 

 carpus of those pairs of perseopoda is, however, in my opinion periodic- 

 al, and may be supposed to have some connection with the fixation of 

 the eggs on the under-side of the body, so I venture the supposition 

 that they are cement-glands. I believe this enormous development 

 of the tibial and carpal glands to be periodical because I have 

 seen fullgrown females of X. armatus and X. Whitei without the 

 joints in question inflated at all; but I have never seen females of the 

 same species with eggs or young ones, which had not at the same 

 time those joints more or less inflated. Thus it seems probable that the 

 development of these glands may be connected with the maternal functions 



Fig. 84. Oxycephalus 

 laiirostris. 



