240 



Figure 15, Plate XXXV, a strong tooth on outer surface much be- 

 fore apex. Three pairs of distinct ventral pseudopods present, one 

 on the posterior margin of each of the basal 3 abdominal segments, 

 each pseudopod armed with a strong curved apical claw that may be 

 retracted at will (PI. XXX, Fig. 2) ; two protrusive blood-gills at 

 base of respiratory tube. 



Pupa (PI. XXX, Fig. 6). — Length, inclusive of respiratory organ, 

 50-60 mm. Color like that of larva. 



One thoracic respiratory organ very long, usually longer than 

 body, the other aborted. Palpi very long, curved forward ; antennae 

 shorter than in Tipulidae and but little curved ; fore tarsi concealing 

 a portion of mid pair; arrangement of parts as in Figure 6, Plate 

 XXXV. 



This species is aquatic, living among floating vegetable debris. 

 The imagines have been taken in various parts of the state, but the 

 only Laboratory record for the larvae is Havana, on the Illinois River. 



Ptychoptera Meigen 



I have found in the collection here a number of larvae of Ptychop- 

 tera taken more than twenty-five years ago by Dr. S. A. Forbes. As 

 the species was not reared and the pupal stage is not in the collection, 

 I am unable to compare the pupae of the genera or to give a specific 

 identification for the form before me. 



Ptychoptera sp. ? 



Larva (PI. XXXV, Fig. 12). — Length, 18-20 mm. with anal re- 

 spiratory tube retracted. Differs noticeably from the larva of 

 Bittacomorpha in the structure of the head and body, none of the cor- 

 responding parts of the two genera bearing more than a general re- 

 semblance to each other. The ventral sclerite of the head is very 

 much broader than in Bittacomorplia and does not narrow so decided- 

 ly posteriorly ; the mandibles differ from those of B. clavipes in hav- 

 ing a number of stout spines on their outer surface before apex instead 

 of a very strong tooth ; the labrum is about 4 times as broad as long ; 

 and the surface of the head is smooth and almost unicolorous. A com- 

 parison of Figures 7 and 10, Plate XXXV, with those of 

 Bittacomorpha (PI. XXXV, Figs. 5, 8) will illustrate the main dis- 

 tinctions between the genera. The body differs from that of 

 Bittacomorpha in lacking the transverse series of wart-like elevations 

 that are so conspicuous in that genus. 



