24 CARL B'OVALLIUS, THE OXYCEPHALIDS. 



each of a double crystalline cone, very long, evenly increasing in thick- 

 ness from the narrowly pointed base to the apex where the Semperian 

 nucleus is distinct; the basal part being surrounded by the ocular pigment. 

 The two halves of the cone are often separated from one another for a 

 considerable part of their length. The cuticular cornea is distinctly facetted; 



Fig 13. 



Fig. U. 



XipJtocephalus 



Fig. 17. 



these facets being, in my opinion, nothing else but an enlarged hexa- 

 gonal reticulation such as that which I have mentioned above as occur- 

 ring in the integument of the body. The number of ocelli arid their size 

 vary much from one species to another, and will be recorded below 

 in the specific descriptions. 



5. The first pair of antennae. 



In the male the shape of the first pair of antennae essentially 

 agrees with that in the other families belonging to the subtribe Hy- 

 periidea curvicornia. The peduncle is three-jointed, but very often the 

 second or third joint is indistinct. The first joint of the flagellum, 

 regarded as the third joint of the peduncle by some authors, is enor- 

 mously developed, much longer and stouter than the peduncle, curved, 

 and bent downwards almost rectangular to the peduncle (fig. 18); the hind 

 convex side is thickly covered with long cylindrical, olfactory hairs, set 

 in regular, transversal rows, each hair being fixed on a small button-like ele- 

 vation. The under side of the first joint is truncated and long, the lower 

 anterior corner often being produced into a thick, obtuse process. The sides 

 of this enlarged first joint of the flagellum often show numerous soft 

 tubercles and small grooves, probably containing cutaneous glands (fig. 19). 



