62 



HARDWICKE'S SCIENCE-GOSSIP. 



also, and this is modified for the purpose. Instead 

 of being soft, and terminating in still softer lobes, it 

 is hard and stiff throughout, and covered with trans" 

 verse strise, and many specimens have large sharp 

 teeth at the tip. In others, however, the teeth are 

 small (as in the drawing, where they can hardly be 

 seen), and in some absent. These teeth are found 

 in all flies of the genus Musca l and are very large in 

 M. meridiana. They are supposed to be used for 

 grinding hard substances. The labrum and lingua 

 are long, but slender. Stomoxys calcitrans abounds, 

 not only in the country, but in towns, and even in 

 London. It sucks the blood of horses and cattle, 

 and causes them much irritation ; but its bite is not 

 poisonous, and leaves no painful swelling like the 

 bite of the Tabanidae. Though this genus belongs 

 to the same sub-family as the previous, it is more 

 nearly allied to the Conopidse, for its mouth greatly 

 resembles the mouths of the genus Conops, while 

 the wings also are somewhat alike ; there are several 

 species and varieties of Stomoxys ; but it is difficult 

 to distinguish them. 



The two principal types of wings in the Muscidse 

 are shown by fig. 30, wing of Tachina virgo, and by 

 the Cordylura's wing in fig. 31. In the wing of 

 Tachina, it will be seen that the prsebrachial vein 

 (pr) is bent at a sharp angle at *, and reaches the 

 edge of the margin close beneath the cubital, while 

 the discal transverse vein (dt) is curved : this is the 

 most frequent form in the Calypteratse. In the 

 Cordylura's wing, on the other hand, the prsebrachial 

 vein is continued straight to the edge, and the discal 

 transverse is straight too : this form is commoner in 

 the Acalypteratse, but occurs also in some of the 

 Calypteratse. There are other less important types 

 and intermediate forms, one of which occurs in 

 M. meridiana, S. calcitrans, and B. geniculatus. and 

 may be seen in fig. 28 : in this type the prse- 

 brachial is curved upwards, but not sharply bent. 



It will be well to notice here that some of the 

 smaller veins which occur in the wings of many 

 other families are absent from the wings of the 

 Muscidse, though the principal veins (which are 

 named in the Tachina's wing, fiig. 30) are the 

 same in this as in other families. Also that, in 

 consequence of the areolets or interspaces near the 

 base of the wing being contracted into a very small 

 compass, the wing is chiefly occupied by the large 

 areolets near the tip, while the discoidal areolet is 

 protracted to such a length as to almost forfeit its 

 claim to be called " disk-like." This may be under- 

 stood by comparing these wings vein for vein with 

 those of Bombylius and Tabanus, given in our former 

 papers (April 1875, p. 80, and July 1875, p. 148). 

 We will now proceed to the Acalypteratae, and 

 begin witli the sub-family Helomyzides (from 'i\og, 

 a marsh, and fivla, a fly, — flies inhabiting marshy 

 ground), which is closely related to the Calypteratse 

 and also to the family Conopidae. The first genus 



is Cordylura ; it includes several species, the most 

 common being C. pubera, represented by fig. 31 > 

 which is frequently met with near rivers and slug- 

 gish streams. It is about the size of the common 

 dung-fly, and not unlike it in shape, but differs from 

 it in several particulars. The colour of the body 

 and head is dark brown, and it is thinly covered 

 with black bristles. The head is large, the face 

 whitish, and the eyes of the colour known as Indian 

 red. The antennse are black, and their bristles 

 fringed. The mouth is of the type common to the 

 Muscidse ; the palpi are black, and have an exceed- 

 ingly long bristle at the tip : this is characteristic of 

 the genus Cordylura. The wings are colourless, and 

 their veins yellow; the femora are brown and the 

 rest of the leg yellow, with black spots on the tarsi ; 

 but the most distinctive feature is the abdomen of 

 the male, which is long and slender, curved down- 

 wards and thickened at the tip, with a wart-like 

 protuberance on the under side (see fig. 31). It is 

 on this account that the genus is named Cordylura, 

 from KopSvXt], a bump, and ovpd, a tail. The tout 

 ensemble of the male is so like some of the members 

 of the Conopidse, that we have made a drawing of 

 it, to aid in its identification and for comparison 

 with the Conopidse, about which we purpose at some 

 time to write. 



F. J. Allen and H. M. J. Underhill. 



NOTES ON THE AQUARIUM. 



WH." is right in thinking "double ane- 

 • mones very unusual." After aquarium- 

 keeping for more than a dozen years, and paying 

 special attention to sea-anemones, I have never seen 

 more than two, which were born and reared in my 

 slate tank. Both were specimens of the common 

 Daisy {Sagartia bellis), and belonged not only to the 

 same variety, but the same family, probably the 

 same mother, who has been in my possession some 

 fifteen years, this stock being specially strong, 

 hardy, and prolific; for, whilst many other indi- 

 viduals have succumbed to various vicissitudes, at 

 different times, and one whole family of pink- 

 disked daisies died out entirely, to my great grief, 

 this robust set live on and multiply to the third and 

 fourth generation, enough to have peopled a hun- 

 dred such tanks, if all the offspring could have 

 found suitable food, care, and accommodation. 



The first Double Daisy lived two or three years, 

 and attained the height of two inches, and died 

 during my absence from home in June, 1875. I 

 believe it died of spring cleaning, or rather of 

 paint, — the outside of the window in which the tank 

 stood was painted. This most valuable anemone 

 was the first to fall a victim ; having taken up its 

 position almost half out of water, it was probably 

 more easily affected by the paint-poisoned atmo- 



