CHLOROPS CHOANITES. 



83 



CHLOROPS (Me-igen). Osciiiis, Latreille. A 

 genus of dipterous insects, belong-in": to the section 

 Athcric/'ra, and family Muscidce. The head is nearly 

 spherical ; the legs are of moderate size and thick- 

 ness, and the body short and not filiform ; the an- 

 tennae are short, and have the seta not branched. 

 These insects, which are of small size, are amongst 

 the most obnoxious of the diptera, attacking various 

 kinds of corn, and almost equalling in their ravages 

 the Cecidomyue. They are of small size, smooth, po- 

 lished, and of a black colour more or less variegated 

 with yellow. To this genus belong the Musca Frit of 

 Linnaeus, and the Musca pumilionis of Bierkander, 

 t>x j iher with upwards of twenty other British spe- 

 cies. The first of these insects, although stated by 

 Messrs. Kirby and Spence not to have been disco- 

 vered in Britain, is doubtingly introduced by Mr. 

 Stephens into his Catalogue of British Insects. This 

 fly, according to Linnaeus, occasionally destroys in 

 Sweden not less than a tenth part of the crops of bar- 

 ley, the loss being estimated at 100,000 golden ducats. 

 The mischief is effected by the insect getting into the 

 ears. An in cresting account of the chlorops pumi- 

 lionis is given by Mr. Markwick, with additional ob- 

 servations by Mr. Marsham, in the second volume of 

 the Linnaean Transactions. This insect was at first 

 considered as the Hessian fly, and no small alarm 

 was produced in consequence thereof ; but the latter 

 author, by pursuing a series of observations by which 

 the real species was determined, proved the incorrect- 

 ness of such a supposition. Early sown wheats are 

 especially liable to the attacks of this fly, the grub of 

 which feeds within the principal stem, just above the 

 root, thereby entirely destroying it ; the root, how- 

 ever, throws out side shoots, so that the injury is not 

 so great as it was at first supposed that it would have 

 been. The perfect flies, as we have stated in our 

 article on the Cecidomyiae, abound in the autumnal 

 months*, swarming in our apartments, so that, from the 

 short-lived existence of dipterous insects in the per- 

 fect state, it seems necessary that, as the flies are pro- 

 duced from the early sown wheat in May, there should 

 be an intermediate generation to produce the autumnal 

 brood ; direct observation is, however, required upon 

 this point. This insect is under a quarter of an inch 

 in length, the thorax having two lateral yellow lines. 

 The maggot is white and fleshy. It is at the period 

 when the wheat is about six or eight inches above the 

 ground (as we learn from a friend who has lately 

 reared some of those destructive insects), that the 

 chief injury is committed. 



CHLOROXYLON (Dccandolle). A lofty East 

 Indian tree, called Siuictenia cldoro.vylon by Roxburgh. 

 It is the green mahogany of the east, and as useful 

 timber is estimable for many purposes of buildinsr. 

 Chloroxylon is also the specific name of one of the 

 West Indian laurels. 



CHOANITES. A name given by Mr. Mantell, 

 in his Geology of Sussex, to a genus of fossil zoo- 

 phytes, which are very numerous, and appear to hold 

 an intermediate place between the Alcyonia, properly 

 so called, and the Ventriculites. They are distin- 

 guished from the former by their having a central 

 cavity in their upper part, and, from the latter, by 

 their being without an external reticulated integu- 



* During the autumn of 1834, they literally swarmed ii 

 mpa tments. even in the immediate environs of London. 

 NAT. HIST. VOL. II. 



ment, &c., and possessing a very slight degree of 

 contractile power. Their forms are various, being 

 enerally either funnel-shaped, spherical, globular, 

 or subcylindrical, having a central opening in their 

 superior part, and appearing to have been originally 

 composed of a parenchymatous substance, capable of 

 imbibing moisture, and of contraction in a slight 

 degree. The base was fixed. 



The Alcijonimii Jicus of Linnceus may be considered 

 as the type of this genus. Parkinson, in his Organic 

 Remains, describes this zoophyte as follows : " It is 

 of the form of a fig, being attached to rocks by 

 branches proceeding from its smaller end ; the upper 

 part is a little flattened, and has a cavity in the 

 centre. Its colour resembles that of tobacco, and its 

 parenchymatous substance cannot be compared to 

 any thing better than to nut-galls when well dried." 

 Org. Rem., vol. ii., p. 96. 



The remains of this genus, which were formerly 

 indiscriminately placed among the A/cyonia,\\ere first 

 noticed by M. Guettard, at Verest, and at Mont 

 Richard, in Touraine, and were described by him in a 

 paper published in the Memoirs of the Academy of 

 Sciences of Paris, 1757. 



He observes that they are of a globular form, 

 having in many examples the base elongated into a 

 pedicle. In the centre of the superior part is a 

 circular opening, generally filled with the substance 

 in which the fossils are embedded. The cavity is 

 larger in its upper part than in the lower, and is con- 

 tinued almost to the pedicle, in some specimens ap- 

 pearing even to pass through it. From the circum- 

 ference of the opening, lines may be traced that not 

 only pass over the whole of the spherical part (where 

 they form striae more or less distinct), but also pene- 

 trate the substance of the zoophyte. There is seldom 

 more than one opening, but instances have occurred 

 in which three have been found. Very accurate 

 representations of these fossils are given in Parkin- 

 son's Organic Remains, vol. ii., pi. 9, figs. 1, 3, 4, 6, 

 8, and pi. 11, fig. 8. 



Three species are described by Mantell. The 

 first of these, the Subrotundus, is that generally termed 

 by collectors the Ficoid alcyonite, from its supposed 

 resemblance to the fig. The surface is smooth, and 

 entirely without markings, and the cavity nearly 

 circular. The second, the Flexuosus, is cup-shaped, 

 the margin of the central depression being marked 

 with flexuous indentations. The radical processes 

 are all long and fibrous. This species is very rare, 

 and, as well as the former one, is found in the 

 Upper Chalk, near Lewes in Sussex. The Konigil 

 is the third, and is described as " inversely conical, 

 externally marked with irregular fibres, some of 

 which penetrate into the substance of the fossil, and 

 terminate in openings on the inner surface. The 

 central cavity is cylindrical, deep, and narrow, and 

 the base fixed by the radical processes." This spe- 

 cies is generally enveloped in large irregular flints, 

 which exhibit but slight traces, externally, of the 

 body which they inclose. The superior part pre- 

 sents a convex surface, with a cylindrical body in the 

 centre, whence interrupted fibres ramify in a radiating 

 manner towards the margin. Numerous perforations 

 may also be observed at the base, which, without 

 doubt, afforded a passage for the radical processes. 

 They are found in abundance in the loose flints 

 beneath the turf, near Lewes race-course, and appear 

 to have been of frequent occurrence in the upper beds 

 



