HARDWICKE'S SCIENCE-GOSSIP. 



159 



species are British, nearly all representing a different 

 genus each ; of Dexia we have five species. The 

 larva of the Dcximc are chiefly parasitic on Lepido- 

 ptera ; the flies frequent flowers and dry, warm spots, 

 and are often found in woods. 



In Desvoidy's splendid work on the " Myodaires," 

 he gives a lengthy list of the species of Tachiniuu: 

 and Dexincc that are known to be parasitic, with the 

 species of insect infested. 



As a rule the abdomen is longer and more pointed 

 in this group than in the Tachini/uc, and as in that 

 group the legs are brittle and easily become detached 

 from the body, 



Frosena siberita^ F., Curt. 665. Tlielaira letuozona, 

 Pz., Pauz. civ. 



(3.) Sarcpphagincc, 



Dr. Meade, a few years ago monographed the 

 British species of this group, which number about 

 twenty, all (with one or two exceptions) being 

 closely allied and exceedingly difficult to identify. 



They breed in decaying animal matter, occasionally 

 in dung. The imagos usually have tesselated black 

 and grey abdomens — with strong spines towards the 

 tip. The thorax is usually longer than it is broad. 



Cynomyia viortiwriim, L., is a large, bright blue 

 fly which breeds in the putrid corpses of animals, 

 generally dogs ; appearing in April and May. The 

 face is bright golden yellow ; the legs black ; wings 

 nearly clear. It is not common here, but is frequently 

 met with on the Continent ; long 8-12 mm. 



Sarcophaga, Mg., is a genus of flies, in which the 

 thorax and abdomen are divided into tessellated 

 squares, the wings are pale grey, the legs black ; and 

 the thorax, abdomen, and legs covered more or less 

 with spines, the number, length and position of these 

 spines being important specific characteristics. 



.5". caniaria, L., the commonest species, is known 

 as the "flesh-fly." 



In some species the extreme tip of the abdomen is 

 bright red. The 9 in this genus is viviparous, 

 20,000 larvag having been found in a single specimen. 



(4.) Muscina:. 



The flies of this group are the greatest scavengers 

 of the order, the larvje living in decomposing animal 

 matter and devouring nearly all the fleshy part of the 

 carcase. Sometimes they breed in dung. 



About thirty species are British, many very 

 common. 



The principal genera may be separated thus : — 



Proboscis horny, projecting horizontally, prominent : Stomoxys, 



Geoff. 

 Proboscis soft, vertical, not prominent. 



Fourth longitudinal vein at its bend upwards not forming 

 a sharp angle. 



Middle tibia spined along its length : Mesembrina, 



Mg. 

 Middle tibia spined only at tip: Cyrioneura, Mcq. 

 Fourth longitudinal vein at its bend upwards forming a 

 sharp angle. 



Species non-metallic. 



Middle tibia spined along its length : CalUphora, 

 Des. 



Middle tibia spined only at tip : Musca, L. 

 Species metallic green : Lucilia, Des. 



Lticilia, Desv., is a genus of bright metallic green 

 flies, the face being usually black or green, the wings 

 nearly clear. 



At least six species are British, all more or less 

 pubescent, and all very closely allied ; long <y-\o 

 mm. 



L, Ccesar, L., and L. cornicifta, F., are the two 

 most common species, appearing everywhere ; the 

 latter being easily known by its bright green face. 

 These flies are sometimes known as "green-bottles." 



CalUphora eiythrocephala, Mg., is the common 

 meat-fly or "blue-bottle;" a closely allied species, 

 C. vomitoria, L., has a red beard. The progeny of 

 this fly is said to amount to 500,000,000 in twelve 

 months ; and Mr. B. Lowne, who has made this 

 species a study for many years, asserts that in the 

 imago " not one structure exists as it exists in the 

 maggot." 



Musca do??testtca, L., is the common house-fly. 

 Black and grey, with rather tawny sides to the 

 abdomen ; antennae, legs, and eyes black ; wings 

 clear ; thorax black, with grey stripes ; face silvery ; 

 long 5-7 mm. 



Mesembrina meridiana, L., is a rather large black 

 haiiy fly,; with black snout and golden yellow cheeks ; 

 black mouth and eyes, black legs, grey wings, tawny 

 at the base and along the fore-border; not un- 

 common ; local ; long lo-i I mm. 



Stomoxys calcitrans, L., is easily recognised by its 

 strong, prominent proboscis. About the size of 

 M. domestica, the abdomen being greyish with black 

 markings ; usually found on sunny days on leaves 

 and wooden posts ; it follows horses in numbers, and 

 causes much irritation by its bite ; long 6 mm. 



Cyrtoiieura stabidans. Fin., greyish, with pale 

 brown reflections, larger tham M. dojnestica, common 

 everywhere, especially in houses. 



It has been bred from shallot, but the species in 

 all probability breeds in a variety of substances. 



(5.) Anthomyincs. 



Of this extensive group of closely allied species, 

 we have over 200 species. In many species it is 

 impossible to identify the 5 , the specific characters 

 being confined to the ^. 



The larvse of many species are leaf-miners, others 

 live in the stalks of plants, in fungi, decomposing 

 vegetable matter, &c., and damage the crops to no 

 inconsiderable extent. 



Dr. Meade published in the " Ent. Month. Mag.," 

 vol. xviii. (188 1 ), a series of articles on this group, 

 and in the number for Oct. 1SS3, gives an analytical 

 table of the higher genera of Antkotnyinis. This 

 group is eminently a very difficult one to classify 



