PHALACROCERA. 307 



in this way, would be analogous to that of most Tipulde. The 

 prsefurca (in P. tipulina) forms a perfectly straight line with the 

 third vein ; the remaining portion of the second vein looks there- 

 fore as if it was emitted from this continuous vein j it is almost 

 angular at the basis, and emits from this angle a short stump of 

 a vein, projecting inside of the marginal cell ; owing to this 

 peculiar course of the second vein, the submarginal cell is square 

 at its inner end, which is in a straight line with the inner end of 

 the first posterior cell. 



In P. replicata the third vein is much less conspicuously in a 

 straight line with the praefurca; the remaining portion of the 

 second vein is gently arcuated, and not angular at its inner end ; 

 there is no stump of a vein upon it ; the submarginal cell is dis- 

 tinctly longer than the first posterior, and hence, their inner ends 

 are not in one line. In both species the second posterior cell is 

 attenuated at the inner end, its line of contact with the discal cell 

 being very short ; in some specimens (according to Dr. Schiner's 

 statement) this cell is actually petiolated ; the discal cell is 

 elongated ; the fifth longitudinal vein is abruptly incurved to- 

 wards the margin at its tip ; the sixth is straight ; the seventh 

 nearly so ; the posterior margin of the wing has the propensity to 

 fold (hence the name of the European species P. replicata). 



Heretofore, only the two above-named species of Phalacrocera 

 have been described. The name of the genus is derived from 

 <paa.axp6?, bald, in allusion probably to the almost glabrous antennae 

 of the European species. 



The larva of P. replicata has been described by Degeer, Yol. 

 VI, p. 351, Tab. XX. It lives in the water, among aquatic 

 plants and mosses, is greenish-brown, bearing a number of long, 

 soft and flexible filaments, looking like spines. It remained all 

 winter in the larva state, although a crust of ice formed on 

 the vessel which contained it. In May, the larvae transformed 

 into pupae and floated in this state on the surface of the water. 

 The posterior end of the pupa has several pairs of hooks, by 

 means of which it can seize the stems of the plants and descend 

 below the surface of the water. 



Description of the species. 



1. P. tipulina 0. S. %. — Fuscescens, capite et thorace supra ob- 

 scure cinereis, hoc obsolete vittato, pleuris canis ; vena lougituclinalis 

 prima in secundam, non in costam, excurrit. 



