186 NEW YORK STATE MUSEUM 



wings lij^aline, small crossveins not darker than the adjacent 

 veins, not clouded with brown, third vein beyond its middle 

 slightl}^ bowing toward the costa; length 2.5 mm. Male. Flag- 

 staff, Arizona. New Jersey (Johnson). 



Thalassomyia frauenfeldi Schiner 

 Theobald in "An Account of Brilish Flies/'' p.2G2, reproducer 

 a note of Mr Swainson, which reads in part as follows : 



'' . . . I found this larva several times on Obelia zoophyte* 

 growing at the end of St Anne's pier. Next I found it on some 

 Ooryne from the Mumbles (Swansea) and more recently I dredged 

 it from fifteen fathoms off Spanish Head (isle of Man) adhering 

 to seaweed. Professor Miall, of Leeds, to whom I sent specimens^ 

 thought it would ultimately turn out that Johnston's C o m p o n - 

 t i a was Schiner's Thalassomyia frauenfeldi. Thi» 

 seems very possible, as the descriptions are very similar. . ." 



The figure given by Theobald (1892) is reproduced on pl.34, fig.l^ 



Genus 38. Chironomus Meigen 

 Illiger's Magaz. 2:260. 180S. (Chironomus, part) 

 Larva. The larvae of this genus differ from those of the other 

 genera of the group Chironomus primarily in the form of 

 the mouth parts, and are known as bloodworms; some species, 

 however, have pale larvae. The antennae are short, with the 

 first joint nearly twice as long as the remaining four taken to- 

 gether. Set on the end of the first joint, there is, besides the 

 second joint an unsegmented appendage. On the under surface 

 of the labrum are several pairs of setae and sometimes a pair of 

 fan-shaped organs, perhaps sense-organs. The epipharynx is well 

 developed, and on each side of it is a long chitinized, sickle- 

 shaped process, which are called the lateral arms in the following, 

 descriptions Cpl.22, fig.lO la. and pl.23, fig.lO Ir) . At the anterior 

 margin of the epipharynx is a minute comb with caudad project- 

 ing teeth (pl.23, fig. 10 c) ; caudad of these is a horseshoe-shaped 

 piece with the open end projecting cephalad (fig.lO). Within 

 this arch are several curved pectinate setae, which may be erected, 

 though they are usually folded down as shown in the figures. The 

 maxilla has, besides the rather prominent palpus, some cephalad 

 projecting filaments on the outer lateral margin and a number of 

 setae, j^apillae and filaments on the inner margin (pi. 22, fig.l mx). 

 The eleventh abdominal segment has usually though not always- 

 two pairs of blood gills besides those on the twelfth segment. 



