50 PACKAED, ON SALT WATER INSECTS. 



Square Island, Labrador, where it probably occurred in 

 a fresh-water or brackish- water lake, for the specimen 

 slipped into my collecting bottle without attracting notice, 

 though had it been found on the sea-shore, it would at 

 once have gained special attention. It differs very slightly 

 from the Illinois puparium, chiefly in the larger abdom- 

 inal legs, i. e. the hooked fleshy tubercles. 



During the past year Mr. J. H. Emerton has detected, 

 at Marblehead, Mass., the puparia of another species of 

 this genus in a salt water pool containing ulvse, etc. 

 They are a little larger, but otherwise closely allied to 

 the Illinois species. I have also received from Dr. T. 

 d'Oremieulx of New York, a puparium, scarcely distin- 

 guishable from the Illinois specimens, which he found 

 under the sea-weed on the shores of JSTarragansett Bay. 



The species from Mono Lake difiers much from the 

 others in having much larger tubercles, the two last pairs 

 being large and prominent. The body 

 is longer and larger, and the segments 

 more convex than in any of the species 

 mentioned above. 

 ^^s- *5- A puparium of a fly allied to Eris- 



talis (Fig. 6) was also received from Mr. Cox, who states 

 that it is found in the brine of the Equality Salt Works 

 associated with Ephydra. 



We can record another salt water Eristalis, a puparium 

 having been found Sept. 5, 1865, by Mr. C. A. Putnam 

 in the salt water canal (of the Naumkeag Factory) lead- 

 ing into Salem harbor. The specimen is in the collection 

 of the Essex Institute. 



It is evidently a Helophilus, agreeing closely with 

 Westwood's figure 131 (8) in his "Modern Classification 

 of Insects," vol. ii. The body of our specimen is cylin- 

 drical, a little flattened beneath, and the cephalic end is 

 somewhat truncated, the tergum sloping rapidly to the 

 head. Just behind the head is a pair of horny slender 

 tubercles, about three times as long as thick, the more 

 anterior pair of tubercles seen in the figure of Eristalis ? 

 (fig. 6) are obsolete in the present specimen. The body 

 is covered with dense fine hairs, and on the under side are 



