760 CHARLES PauL ALEXANDER 
elongate lobe which is indistinctly pseudo-segmented, in its posterior 
part being in intimate connection with the abundant fat tissue. 
Resptration and circulation 
The most important literature on the respiratory and ceca organs 
is as follows: 
Ptychoptera. Grobben, 1876. 
Dicranota. Miall, 1893: 245-248, 
Phalacrocera. Miall and Shelford, 1897: 351-356. 
Liogma. Miiggenherg, 1901. 
Ctenophora. Anthon, 1908: 551-554. 
Holorusia. Kellogg, 1901a; Comstock and Kellogg, 1904: 57-58, 60. 
Tipula maxima. Brown, 1910. 
Tipulinae, Hexatomini (especially Tipula paludosa and Limnophila punctata). Gerbig, 
1913. 
General articles. De Meijere, 1895; Viallanes, 1880. 
The most important works on the structure of the tracheal system with 
special reference to the mechanics of the spiracles, are those by Miiggen- 
berg (1901), De Meijere (1895, 1992, 1916), Brown (1910), and Gerbig 
(1913). Miall and Shelford (1897:351-356) discuss in much detail the 
structure of the heart in Phalacrocera. 
In Eriocera spinosa, which may be considered as typical for this group 
of crane-flies, there are two principal tracheal trunks which lie in a dorsal 
position and run almost the length of the body. They are connected 
across by a very delicate, unbranched, simple, tracheal commissure, and 
send off branches laterally to supply the various organs of the body. Near 
the posterior end of the body they are approximated, and just in front of 
the spiracles they expand into the tracheal chamber. Directly cephalad 
of this chamber the first lateral branch passes off, numbering from the 
posterior end forward. Branches 2 to 8 are large and much forked. 
Just after leaving the main tracheal trunks, each of these sends off a 
ventral branch which supplies the alimentary canal and the fat tissue. 
Branch 3 supplies the region of the malpighian tubules; branch 4, the 
posterior part of the stomach; branch 5, the anterior part of the stomach; 
branches 6 to 8, the esophageal region — branch 6 supplying the pro- 
ventriculus, branch 7 and part of branch 8 the esophagus, and the remainder 
of branch 8 the pharyngeal region. 
The main part of each lateral branch continues laterad, at its first 
(anterior) fork sending a branch forward to the next branch, so as to 
