186 \K\V MiKK STATi: Ml SKIM 



wings hyaline, small crossveins not darker than I he adjacent 



veins, not clouded with In-own, third vein beyond its middle 



slightly bowing toward the costa : length 1'..") mm. Male. Flag- 

 staff, Arizona. New .Jersey i. Johnson i. 



Thalassomyia frauenfeldi Schiner 



Theobald in "An Acconni oi i'.riiish Files." p.L'Oi', reproduces 

 a note id' .Mr Swainson. which reads in part as follows: 



. . . I found this larva several times on Obelia /oophytes 



gro\\ ing at tl ml of St Anne's pier. Next 1 found it on some 



< 'oryne from the. Mumbles t Swansea i and more recent ly 1 dredged. 

 ii from lifteeii fathoms oil Spanish lle;id I Isle of .Mam adhering 

 to sea \\eed. Professor .Miall. of Leeds, to whom I sent specimens, 



thought it would ultimately turn out that .Johnston's Compon- 

 tia was Schiuer's Thalassomyia Irauenfeldi. This* 

 seems verv j:ossiJi!e. as the descript ions are \er\ simihr. . ." 

 The figure given by Theobald i iS'.ll'i is reproduced on pl.-'M, lig.l. 



Genus 38. Chironomus Meigen 

 miner's MUI.M/.. _ :'_';o. Iso:;. ' h i r o u o ni u s , p.-irl i 



Larva. The larvae of this ^enns dill'er from those of tl ther 



genera of the -jronp < ' h i r o n o m u s primarily in the form of 

 the month paits. and are known us Idoodworms; some species, 

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

 first joint nearly twice as lou^- .-| S the remaining four taken to- 

 li'i ther. Set on the end of the lirsi joint, there is. liesides the 

 second joint an nnseumented ap]iendaue. On the under surface 

 of the labi-um 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 loni;- chitinized, sickle- 

 shaped ]irocess. which are called the lateral arms in the following 

 descriptions i pl.1'1'. ti^.10 la. and jd.l'.'l. ti<;-.lll lr). At the anterior 

 margin of the epipharyn-x is a minute comb with candad jn'oject- 

 ing teeth (pi .-3, fig. 10 c) ; candad of these is a horseshoe shaped 

 piece with the open end projecting cephalad (fig.lOi. 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, papillae and filaments on the inner margin ipl.-l', fig.l mx). 

 The eleventh abdominal segment has usually though not always 

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



