SYRPHID^. 



399 



Fig. 318. 



flowers in the spring, and are common throughout the sprino-. 

 They scoop up the pollen of the flowers with their maxillge. 

 We have received from Mr. E. T. Cox the 

 puparium (Fig. 318) of a species which in- 

 habits the salt vats of the Equality Salt 

 Works of Gallatin County, 111. The pupa- 

 rium of a species of Helophilus closely re- 

 sembling that figured by Westwood (Class. Insects, Fig. 131, 

 8), has been found living in the salt water canal of the 



Nanmkeag Factory leading 

 into Salem Harbor, and is in 

 the Museum of the Peabody 

 Academy. 



Closely allied to Eristalis is 

 the genus Merodon, of which 

 31. hardus Say (Fig. 319 ; o. 

 puparium, natural size) is ft-e- 

 Fig. 319. quently met with. Its thorax, 



the first abdominal ring and the side of the second are cov- 

 ered with short yellow hairs ; it is .70 of an inch in length. 

 The puparium is of the same length, and 

 is cylindrical, ending suddenly in a re- 

 spiratory filament a little longer than the 

 body ; it is quite stout, contracting be- 

 yond its middle into a slender filament. 

 On each abdominal ring is a pair of small, 

 low, flattened tubercles crowned by a 

 number of radiating spinules. Its larva 

 is undoubtedly aquatic, like that of Eris- '^' 



talis. Mr. Sanborn has also reared from the pupa state M. 

 Narcissi, which probably lives in the soil about 

 decaying bulbs, as the puparium has no respira- 

 tory tube, but instead a very short sessile truib 

 cated projection, scarcely as long ay it is thick 

 with a pair of stigmata in the end ; the body is 

 cylindrical and rounded alike at each end, with a slight con- 



ries perfectly vivified; it is fi true arterial blood. Tliese capillaries arc not m 

 communication with the venous capillaries; the blood is taken up by the tissues, 

 it uourishes them and flows into the venous lacunas, and the lacunar cun-ents 

 carry it to the dorsal vessel." Annalcs des Scie7ices Xuturelles, 18G8. 



