250 



Ephemerid-i;.- 



-INSECTS.- 



-LlBELLlXID^. 



the Pteronarcys resembles an amphibious animal in its 

 habit of hfe, and may be designated "an Insect Protetts 

 among the winged Articulata — the representation in 

 structure, as it appears to be in habit, of the Proteus 

 of Vertebrata. Its organs of respiration fully justify 

 us in instituting this comparison. The true Proteus 

 has both lungs and branchis ; and a similar conforma- 

 tion of structure exists in Pteronarcys, in so far as the 

 ramified frachese being the direct recipients of atmos- 

 pheric air, are to be regarded as the representatives of 

 lungs." — Linn. Trans., vol. sx., p. 4,33. 



Most of the Canadian Perlida; in the daytime retreat 

 to the cracked fissures of decayed trees. Mr. Barnston 

 noticed that the species called Capnia vernalis comes 

 out of the water in the nymph state in the cracks of the 

 ice, and casta its skin there ; this it does when the 

 thermometer indicates that it is freezing. 



Family— EPHEMERID^ {Mat/ Flies). 



This is a family of important insects, seeing that they 

 furnish much food to fresh-water fishes. The antennje 

 are very small (Plate 6, fig. 9, Ephemera vulgata). The 

 mouth is nearly obsolete in the perfect insect ; indeed, 

 ill that state they only live a few hours ; hence their 

 name Ephemera. The metamorphoses of these insects 

 are very interesting ; but space prevents me from enter- 

 ing on the detail. They abound in New Zealand. One 

 species, E. albipennis, with white wings, is common in 

 Europe. Swarms of this species are often met with ; 

 tliey resemble in this state a fall of snow. The dead 

 bidies are at times collected in some parts of Europe 

 as manure. 



FA.MILY— LIBELLULID^ {Dragon-flies). 



Dr. Hagen records forty-six British species.* He 

 places them in the following sections : — 



Tribe I. — Winga not similar; the hind ones dilated at the 

 „ base. 

 i'Div. 1. — Lower lip smaller than the palpi. 



1. Sub family LiBELLULiNA. Eyes simple, not prolonged pos- 

 teriorly. Larva of LUellula depressa, figured Plate 6, 

 fig. 3. 

 Genus LibeUula, with thirteen species. 



Fig. 153. 



2. Sub-family CoRDULINA. The eyes with a slight prolonga- 



tion backwards. 

 Genus Cordidia, with four species. 

 Div. 2. — Lower lip larger than the palpi. 



3. Sub-family GoMPHiNA. — Eyes not contiguous, or scarcely so. 



* See his Synopsis in Stainton's Entomologist's Annual for 

 1857, p. 39. 



Genus Oomphus. — Eyes remote ; lower lip rounded at the tip. 

 Three British species. 



Genus Cordvlegaster. — Eyes slightly contiguous, lower lip cleft 

 at the end. One British species. 



4. Sub-family JSschnina. — Eyes completely contiguous. 



Genus jEschna. — Anal angle of hind wings sharp in the male 

 and rounded in the female. Seven species. Of these, 

 one species (jE. borealis), previously to its being taken in 

 Scotland by M. De Selys during a short visit, was not 

 known as British ; so that the entomologist who examines 

 carefully the mountainous parts of this country, may 

 expect to meet with species of Dragon-flies not j-et re- 

 corded as British. 



Genus Anax. — In this genus the anal angle of the hind wings 

 is rounded in both sexes. One British species. 



Tribe II. — The fore and hind wings in this tribe are similar. 



Div. 1. — Anlecubital nervures numerous. 



.=1. Sub-family CALorTERYGiNA contains the larger species of 

 the tribe. 



Oenus Calopteryz contains two species found in Britain. 



Ihv- 2. — With two antecubital nervures. 



6. Sub-family Agrioniha contains the smaller species of the 

 tribe. 



Genus Platycnemi.«, with one British species, may be known 

 by the tibire being dilated. 



Genus Lestes, with five British species. — The tibiae are cylin- 

 drical, and the stigma of the wing is large and oblong. 

 Plate 6, fig. 1, represents the Lestes sponsa. 



Genus Agrion, with nine British species. — This genus has the 

 tibiae cylindrical, and the stigma of the wing is small and 

 rhomboidal. 



The wings of the Dragon-flies are nearly equal in size 

 and form — a complete and beautiful piece of network, 

 which resembles the finest lace, with the meshes between 

 filled with a pure, transparent, glossy membrane. Some 

 of the genera have wings always expanded, even when 

 tlie creatures are resting, so that they can on being 

 disturbed take fliglit in an irstant, there being no 

 necessity for them to unfold their wings. These 

 insects can fly in all directions without turning — back- 

 wards and forwards, and to the right or left, so that 

 to those inexperienced in their habits they are very 

 difficult of capture. The smaller Dragon-flies are 

 equally alert. Specimens are sometimes taken at sea 

 at great distances from land ; thus Mr. Davis mentions* 

 one which flew on board the vessel in which he sailed 

 when she was five hundred miles from land. 



The figure (Plate 6, fig. 2) represents a fine New 

 Zealand species of Dragon-fly named Petalura Car- 

 rovei. 



The species Cahpteryx and the allied Agrions are 

 often very beautiful. Here come 



" The beautiful blue damsel flies 

 That fluttered round the jasmine stems. 

 Like winged flowers or flying gems." 



to which the poet Thomas Moore refers. 



Mr. Gosse, when in Alabama, noticed a large dragon- 

 fly actually try to get some fish out of a shallow pool. The 

 dragon-flj' had been hawking to and fro over the brook 

 some time ; at length he dashed down into the water 

 where a few of the fry were swimming, and made 

 quite a little splash, but did not go under. He rose 

 again immediately, but without success evidently, as 

 he continued his hawking as before. The fry darted 

 away in all directions from the intruder's attack, of 

 course, but soon reassembled and came to the surface 

 as before. The dragon-fly, not discouraged by failure, 

 presently made another pounce, and now succeeded 

 ' Entomological Magazine, vol. v., p. 251. 



