CULICIDiE. 



[ 178 ] 



CUSCUTA. 



canal (PI. 26. figs. 30 & 31 e), representing 

 the labrum, forming the most robust part of 

 the mouth, except the labium. 2. A pair of 

 slender needle-like pieces, the mandibles, 

 serrated on the inside near the tip (PI. 26. 

 figs. 30 & 31/), thickened at the back, like 

 a scythe, and transversely striated. 3. A 

 second pair of very delicate and slender or- 

 gans (PI. 26. figs. 30 & 31 g), dilated at the 

 base, to which the palpi are attached, repre- 

 senting the maxillae. 4. A slender needle- 

 like instrument, lanceolate at the end, tra- 

 versed b}^ a narrow canal (PL 26. figs. 30 & 

 31 d), the analogue of the tongue. 5. The 

 outer tubular canal (PL 2(d. fig. 30 i), in 

 which the others are lodged when at rest, 

 and representing the labium. The labrum 

 and labium are each traversed by a longitu- 

 dinal slit throughout their length. 



It appears that in the males the labrum 

 and tongue are absent. It has been sup- 

 posed that when the lancets of the female 

 gnat are introduced into the skin, a veno- 

 mous liquid is simvdtaneously instilled into 

 the wound, and that the great irritation pro- 

 duced may thus be accounted for. It is 

 more probable, however, that this arises from 

 the deeper penetration of the lancets into 

 the skin, for they are of great comparative 

 length, — about four times that of the lancets 

 of the flea. 



The eggs are deposited in a small boat- 

 shaped mass, which floats upon the surface 

 of the water. They are oval, with a small 

 narrow knot at the top, and are arranged 

 side by side, and closely packed. 



The larvae inhabit standing waters, and 

 may be observed frequently, during the 

 spring and summer, jerking themselves about 

 with great agility, or sus])ending themselves, 

 for the ])urpose of respiration, immediately 

 below the surface of the water, with the 

 head downwards. The head (PL 28. fig. 1) 

 is distinct, large, rounded, and furnished 

 with two unjointed antennae, and several 

 ciliated appendages, which serve for obtain- 

 ing nourishment. The thorax is furnished 

 with bundles of feathery hairs ; the abdomen 

 is long, nearly cylindrical, much narrower 

 than the front parts of the body, and divided 

 into ten segments, the eighth of which is 

 funaished with a long respiratory air-tube, 

 terminated by a small star ; the last joint is 

 terminated by setae, and by five conical slen- 

 der plates. 



After several raoultings, the larvae are 

 transformed into pupae, which also move 

 about with agility by means of the tail and 



two terminal swimming organs. In this 

 state they take no food ; and the position in 

 which they suspend themselves in the water 

 is the reverse of that previously assumed, 

 i. e. the head is upwards. The respiratory 

 organs consist of two air-tubes placed upon 

 the thorax, and the body is much curved. 

 The final transformation takes place in three 

 or four weeks, the exuviae of the pupa serving 

 as a raft, upon which the insect remains un- 

 til its wings are extended. 



BiBL. Westwood,Jw^rocZMC^2Ow,4'c.p.507; 

 Robineau Desvoidy, Mem. Soc. d'Hist. nat. 

 iii. 1827, p. 390; Stephens, Zool. Journ. 1 ; 

 Curtis, Brit. Entomol. xii. 537. 



CUPRESSINEiE.— A suborder of Coni- 

 ferae (Gymnospermous Flowering Plants), 

 distinguished from the Abietineae by the 

 erect ovules and spheroidal pollen-grains. 

 The pollen-grains of the Cupressinea; divide 

 into two unequal cells, the larger of which pro- 

 trudes as the pollen-tube, while the smaller 

 remains unchanged. Further particvdars will 

 be found under Conifer/E and Wood. 



CUPRESSUS, Tournefort.— A genus of 

 Cupressineae, of which the Cypress, C. sem- 

 2)€rvirens, is an example. See Conifers. 

 CURCULIO, Linn. — A genus of Coleop- 

 terous Insects, of the family Curculionidae 

 (weevils). 



Curculio im23erialis, the diamond-beetle, 

 is well known on account of the splendid 

 colours which it exhibits. Many other mem- 

 bers of this family present colours almost 

 equally brilliant. These colours are pro- 

 duced mainly by the action of minute scales 

 upon the incident light. See Scales of 

 Insects. 



The oral organs of the Curculionidae are 

 curiously ])laced at the end of an elongated 

 rostrum which represents the head, and to 

 the sides of which the antennae are attached. 

 BiBL. Westwood, Introduction, Sfc; Ste- 

 phens, British Beetles. 



CURCUMA, L. — A genus of Zingiberaceae 

 (Monocotyledons), remarkable on account of i 

 the tuberous rhizomes. Those of C. long a 

 form the substance called turmeric, and j 

 the starch from the cells of the young tubers ' 

 forms one of the kinds of East Indian arrow- 

 root. The tubers of other species yield very 

 pure starch, and furnish East Indian arrow- 

 roots. The grains of an unknown Curcuma 

 imported under that name are represented 

 in fig. 19 of Plate 36. 



CUSCUTA, Tournefort. — A curious genus 

 of Convolvulaceae (Dicotyledons), consisting 

 of parasitical, leafless plants, annual or per- 



