August 25, 1893.] 



SCIENCE. 



107 



NOTES ON MARINE AND EEESH WATER LARV^ 

 OF MIDGES. 



BY GEO. SWAINSON, F. L. S., ST. ANNE'S-ON-THE-SBA, ENG. 



DuBiNG the i^ast two years Professor Miall, P. R S., has 

 been lecturing before the Eritish Association and else- 

 where on "Some clifSculties in the life of aquatic insects," 

 and especially instancing- the larva of the dipterous fly 

 Ghironornus. My interest in this lecture when heard at 

 Cardiff was heightened by the fact that I had on three 

 occasions captured a marine larva very closely resembling 

 his chironomus. This was included by Dr. Johnston 

 amongst the British Marine Annelids under the name of 

 Gampontia cruciformis. {London Mag. of Nat. Hist, Vol. 8, 

 p. 179, Nov. 13, 1834, and "Johnston's British Worms."). 

 That aampontia was a dipterous larva was suspected by 

 both McLeay and Green, the latter because he captured 

 a fresh-water chironomus larva, and noticed its resem- 

 blance to cwnjyontia, and observed its metamorphose into 

 the pujDa stage, but the fly escaped him, and this fresh- 

 water genus remained unspecified. This was in 1837, and 

 since that time no one in England seems to have taken the 

 trouble to find out campontias fresh-water relations. 



tute. Vol. 6, -p. 42). I have carefully compared my speci- 

 mens with the drawings given by Dr. Packard, and it is 

 quite certain they are not the same species, the mandibles 

 being slightly different, but more particularly the hook- 

 lets or retractible claws on both the fore and hind feet 

 are very different, and the respiratory tubules possessed 

 by camp>ontia are not visible on the American species. 



The great difficulty I experienced in finding any one in 

 England to assist in naming this and other species of 

 chironomus larvie I have met with, in a large measure 

 promi^ted me to write this paper. I have ai^jslied to, 

 many of the jJi'incipal authorities on diptera, only to find 

 that there are several families in which the life history of 

 only a very few species has been worked out. Surely 

 there are many excellent members of our microscopical 

 societies throughout England who only need to have the 

 fact brought home to them to induce them to make some 

 attempt, however feeble, to fill uj) this gaj?, especially as. 

 the subject is a very interesting one, and the material 

 abundant. The difficulty of obtaining specialists to un- 

 dertake the work of describing many groups of insects 

 has been recently referred to by the editor of Naiural 

 Science, for he states that, though Mr. Whymi^er's "Trav- 



CAMPONTIA CRUCIFORMIS (a supposed annelid worm). 



a. Natural size. 



b. Magnified. 



c. The head slightly compressed between plates of g 



In October last, on our Golf links at St. Anne's-on-the- 

 Sea, I found several larvae of chironomus fully grown in 

 its splendid blood-red color. These I kept during the 

 winter, and watched their metamorjjhoses in small glass 

 jars, with the tops covered with muslin. They ultimately 

 proved to be C. doraalis, and their resemblance to Gam- 

 jDontia cruciformis in all but color is most remarkable. 

 The hsemoglobin, which colors the blood plasma in the 

 "Harlequin" larva so beautifully, is replaced in the marine 

 form by a light sea-green pigment with which the fat 

 cells are colored. The mandibles and two pairs of re- 

 tractible hooked appendages, or j)ro-legs, are very similar 

 to G. doi'salis, and especially the respiratory tubules at 

 the posterior, and I had therefore no doubt as to Gampon- 

 tia cruciformis of Johnston being a dijsterous larva of the 

 chironomus genus. I found this larva several times on the 

 obelia zoophytes growing at the end of St. Anne's Pier, 

 Lancashire, England. Next I found it on some coryne from 

 the Mumbles, Swansea, and more recently I dredged it 

 from fifteen fathoms dejJth off Spanish Head, Isle of Man, 

 adhering to seaweed. Dr. Packard, of America, has re- 

 corded the discovery of a marine dijaterous larva in fif- 

 teen fathoms off Salem Harbor, which he has named 

 Ghironornus oceanicus (see Transactions of Essex Insti- 



d. Under side of the anal segment. 



e. Hooked sucker foot from Mr. Swainson's micropho- 

 ass. tograph. 



els amongst the Great Andes of the Equator" was com- 

 pleted twelve years ago, the volume in which the zoolog- 

 ical collection was described, has been only recently 

 issued, and this with several large grouj)s of insects 

 omitted, as no one has been found able to describe them. 

 Professor Miall, to whom I sent my sj)ecimens, thought it 

 would ultimately turn out that Johnston's camiMntia was 

 Schiner's Thalassomyia fi-auenfeldi. This may prove to 

 be so, but, again, Schiner only records the capture of the 

 female fly and gives no account of the larvae in his "Fauna 

 Austriaca" (p. 59G, Vol. 2). This species is British, for Mr. 

 H. N. Ridley, of the British Museum, captured both the 

 male and the female flies in a cave in the Isle of Wio-ht 

 {Entomological Mag. for 1884), and I think it is the same 

 fly I have seen more than once on our pier end at St. 

 Anne's-on-the-Sea, but did not succeed in cajituriug them. 

 There is no drawing jDublished yet, I believe, of Tlialas- 

 somyia frauenfeldi. I have twice tried to rear Gampontia 

 cruciformis in a small salt-water aquarium, but unsuccess- 

 fully. It seems quite certain that the larvte of these dd]}- 

 tera do inhabit salt water, for Agassiz speaks of them in 

 the "Cruises of the Blake" as being commonly met with 

 off the North American shores. 



Leaving these species for future identification, I must 



