332 



JOHN B. SMITH. 



Fig. 13. Mouth parts of Stratiotnyid. 



First among these is a small Stratiomyid, of which, unfortunately, 

 my material was too scant to make out all the parts as thoroughly 

 as I desired. It is a small species, caught on the windows of my 

 laboratory, and the figures are from one of the two specimens taken, 

 the other being spoilt in dissecting. The galear structure shows ex- 

 cellently well. The subgalea is evidently divided, surmounted by 

 the two galear joints, each of which is distinct, outwardly chitinous, 



inwardly with a delicate 

 membrane, in which the 

 pseudo-trachea are well de- 

 veloped. In the specimen, 

 more obviously than in the 

 figure, the character of the 

 central chitinous support- 

 ing rods as fragments of 

 the galea joints, is evident, 

 and we have here, practi- 

 cally, the structure of the 

 Simuliid galea, the inner face completed by a membranous expansion 

 and tracheate. 



The palpifer is here reduced to a mere rudiment, without any 

 l)asal process, and in natural position reaching barely to the center 

 of the galear envelope. The labial structure is peculiar, and I re- 

 gret that I had no specimens for further study. There is a fulcrum 

 very like that found in the mosquito, and entering that centrally is 

 the flattened, slightly concave labium or ligula, in which I could not 

 trace any division of parts. The lacinia is a mere enveloping lappet, 



whose point of attachment 

 is not satisfactorily made 

 out. Altogether, the form 

 is a valuable one, and the 

 Stratiomyidae may present 

 characters of great interest 

 where abundant material 

 for dis.section is at hand. 



A very distinct advance 

 is seen in the Leptidse, spe- 

 cies undetermined. The 

 subgalea is united, and, while the chitinous parts of the galea joints 

 are well distinguished, the enveloping membrane covers the whole 



Fig. 14. Mouth parts of Leptid. 



