THE CRANE-FLIES OF NEW YORK PART II 761 



form a complete but much-branched lateral trachea. The branches are 

 very diffuse and abundant and the skin is well supplied. As already 

 stated, the cross-commissures are very delicate and are unbranched or 

 nearly so, the dorsal regions of the body being supplied by branches from 

 the lateral supply. 



The condition of the tracheae in Antocha, the only apneustic crane-fly 

 larva among the species here considered, may be outlined as follows: 



The usual two principal trunks are present, joined across on each 

 segment by delicate cross-commissures which send off two approximated 

 branches except on -the eighth segment. Laterad and ventrad of the 

 principal trunks are the delicate lateral tracheae. These are joined to 

 the main trunks by fine branches inserted about midway between the 

 dorsal commissures, toward the posterior end of the body lying nearer 

 the posterior commissure than the anterior one. 



At the ninth segment each trunk sends off a branch from its proximal 

 side, these branches being connected by a long commissure and supplying 

 the posterior pair of gills. The commissure is about as long as that part 

 of the branch between it and the trunk. Immediately caudad of, or 

 just at, the fork, but on the ventral side, a subequal branch passes into 

 the anterior gills; at the same point the delicate lateral tracheal trunk 

 finally ends in the main trunk. Caudad of this triple forking the main 

 trunk gradually widens out into a cylindrical structure which is truncated 

 apically, at the tip passing out into two small elongate branches, near 

 the base with about three delicate branches, two being dorsal in position 

 and one more lateral. All of these tracheae, to the gills and to the caudal 

 lobes, send off many branched capillaries at frequent intervals, and the 

 caudal lobes unquestionably function as tracheal gills. 



A comparison of Antocha with Dicranota as described and figured 

 by Miall (1893:245-248) shows, in the latter, distinct spiracles and the 

 gills similar but much smaller. The tracheal arrangement differs in that 

 a single branch on either side supplies both gills of that side, while the 

 caudal lobes are tracheated by a branch that leaves the main trunk close 

 to the spiracles. (Plate XII, 2 and 3.) 



The arrangement of the tracheae at the base of the wing pad is described 

 and figured for Bittacomorpha by Dr. Chapman in Comstock's The 

 Wings of Insects (1918:36-37). 



