DEPAZEA. 



DESMIDIACEJS. 



DEPAZEA, Fries. See SPH^RIA. 

 DEPOSITS, URINARY. See URINE. 

 DERMANYSSUS, Duges. A genus of 

 Arachnida, of the order Acarina, and family 

 Gamasea. 



Char. Body soft ; palpi free, filiform, the 

 fifth (last) joint smallest ; labium acute; 

 mandibles: of the male chelate, external 

 finger very long ; of the female, ensiform ; 

 coxae approximate; anterior legs longest; 

 last joint of legs terminated by a bilobed 

 caruncle and two claws. 



D. avium (PI. 2. fig. 24). Found in the 

 cages of tame singing birds. Body ovate- 

 oblong, depressed, slightly broader, and 

 sometimes emarginate posteriorly. The sixth 

 joint of the legs (c) is the longest. Mouth 

 forming a kind of moveable head attached to 

 the under part of the anterior margin of the 

 body; it consists of 1, a triangular labium, 

 pointed in front, and with two palpi ; 2, the 

 palpi (fig. 24 t) the second joint largest, 

 the fifth smallest and accompanied by a large 

 but short, moveable, external seta ; and 3, 

 the two mandibles (b, of female ; af of male). 

 Red or reddish-brown. 



D. vespertilionis. Found upon the mouse- 

 coloured bat (V. murinus). Rostrum or 

 labium nearly as long as the palpi, broad or 

 oval at the base, narrowed in front, cleft 

 longitudinally above, and containing the two 

 long and slender mandibles. 



D. pipistrellcB. On the common bat ( V. 

 pipistrellus). 



D. hirundinis. In the nest of the swallow. 



D. gallincB. On the common fowl. 



Other species are found on the noctule 

 bat ( V. noctula), the merlin, the turkey, the 

 common snail (H. pomatia), serpents, &c. 



Two doubtful species are described as oc- 

 curring upon the human body, one of them 

 in ulcers. 



BIBL. Duges, Ann. d. Sc. nat. 2 ser. ii. 

 p. 19; Gervais, Walckenaer's Arachn. iii. p. 

 222 ; Busk, Micr. Journ. 1842. ii. p. 65. 



DERMESTES, Linn. A genus of Cole- 

 opterous Insects, of the family Dermestidae. 



Char. Maxillary palpi shorter than the 

 maxillae ; antennae short, club large, three- 

 jointed. 



D. lardarius (the bacon-beetle). Black ; 

 base of the elytra with a gray transverse 

 band with black points. Length about 1-3". 



The larva is about half an inch in length, 

 gradually narrowed towards the end of the 

 body, and terminated by a truncated cone 

 with a fleshy lobe at its tip, which is em- 

 ployed as a proleg; the segments of the 



body are clothed with long, scattered brown 

 hairs (PI. 1. fig, 1), and protected above by 

 a coriaceous plate, the last segment having 

 a pair of short, curved, horny spines; the 

 head is scaly, with six small ocelli on each 

 side, and two short three-jointed antennae. 

 The hairs of the larva are used as test-objects. 

 See HAIRS and TEST-OBJECTS. 



BIBL. Westwood, Introduction, fyc. ; 

 Curtis, Brit. Insects, 682. 



DERMESTID.E. A family of Coleop- 

 terous Insects. 



Char. Antennae short, clavate, not elbowed; 

 labrum very short, with a membranous tip ; 

 mandibles short, thick, toothed at the tip, and 

 concealed beneath the labrum ; legs partially 

 contractile, the five-jointed tarsi not folded 

 under the tibiae when at rest, the latter 

 long and narrow ; body ovoid or oblong, 

 thick, rounded at each end, and clothed with 

 hairs or scales ; head short, deeply immersed 

 in the cavity of the thorax, which is trapezoid 

 and broadest behind. 



The larvae of these insects create great 

 ravages amongst dried skins, furs, &c.; they 

 also feed upon feathers, bacon, books, paper, 

 mummies, &c. They are particularly inter- 

 esting to the microscopist, on account of the 

 peculiar and beautiful structure of the hairs 

 existing upon their bodies. 



There are five British genera : Anthrenus, 

 Attagenus, Megatoma, Tiresias and Der- 

 mestes. 



See DERMESTES. 



BIBL. Westwood, Introduction, fyc. 



DESMARESTIA, Lamx.A genus of 

 Sporochnaceae (Fucoid Algae), consisting of 

 olive or brownish sea-weeds, with repeatedly 

 pinnate, feathery fronds, from one to several 

 feet long, growing chiefly between tide- 

 marks or in deep water. The characters of 

 the reproductive structures have not yet been 

 made out, as the species rarely fruit on our 

 coast, although the plants are common. 



BIBL. Harvey, Brit. Mar.Alg. 23. pi. 5D.; 

 Phyc. Brit. 49. 115; Greville, Ala. Brit. 

 pi. 5. figs. 1 to 6. 



DESMIDIACE.E (PI. 10). A family of 

 Confervoid Algae, consisting entirely of mi- 

 croscopic flexible organisms inhabiting fresh 

 water,scarcely a specimen of which can be found 

 that does not contain some of them. They 

 occur in greatest abundance in clear pools in 

 open exposed situations, the larger species 

 being generally found nearest the bottom. 

 Sometimes they adhere in large quantities to 

 aquatic plants, forming green films investing 

 these ; at others they rest as a thick coating 



