S P H 



Itiade by thofe diameters, the radius being I, will be the 

 content. That is, dc ess x -5236 = the content ; c being 

 the conjugate diameter to d, and s the fine of the angle 

 made by the diameters. For the demonltration of this 

 rule, fee Hutton, ubi infra. 



Hence, if d=T, the rule becomes |/>TC'' for the 

 oblong fpheroid : and it d—C, it will be ^^pCT' for 

 the oblate fpheroid : and if T, C, and d, be all equal, the 

 rule will be ^pd'' for the fphere. See Mensuration. 

 Hutton's Menl'uration. 



For the method of finding the fuperficies of a fpheroid, 

 fee Superficies ; and for the folidity, fee Solidity, and 

 the preceding article. 



Dr. Halley has demonftrated, that in a fphere, Mercator's 

 nautical meridian line is a fcale of logarithmic tangents of 

 the half complements of the latitudes. But as the earth 

 has been found to be a fpheroid, this figure will make fome 

 alteration in the numbers refulting from Dr. Halley's theo- 

 rem. Mr. Maclaurin has therefore given us a rule, by 

 which the meridional parts to any fpheroid may be found 

 with the fame exaftnefs as in a fphere. We have alfo an 

 ingenious treatife of Mr. Murdoch's on the fame fubieft. 

 See Phil. Tranf. N°2I9. 



Mr. Cotes has alfo demonftrated the fame propofition, 

 Harm. Meuf. p. 20, 21. See Meridional Parts. 



SPHEX, in Entomology, a genus of infefts of the order 

 Hymenoptera, of which the generic charadler is as 

 follows. The mouth is formed with an entire jaw ; the 

 mandibles are horny, incurved, and toothed ; the lip is 

 horny and membranaceous at the tip ; it has four feelers ; 

 the antennae have about ten articulations ; the wings in 

 each fex are plane, incumbent, and not folded ; the fting 

 is pungent, and concealed within the abdomen. The 

 infefts of this genus are faid to be the moft favage and rapa- 

 cious of this clafs of beings : they attack whatever comes 

 in their way, and by means of a poifonous fling, overcome 

 and devour other; far beyond their own fize. Thofe of 

 divifion B, hereafter to be defcribed, are found chiefly on 

 umbellate plants ; the larvx are without feet, foft, and 

 inhabit the body of fome infeft, on whofe juices they exilt ; 

 the pupa has rudiments of wings. 



" As the infefts," fays Dr. Shaw, " of the genus Ich- 

 neumon depofit their eggs in the bodies of other living 

 infefts, fo thofe of the genus Sphex depofit their's in dead 

 ones, in order that the young larvae, when hatched, may 

 find their proper food." There are more than a hundred 

 fpecies of the genus Sphex, which are feparatcd into 

 divifions. 



Species. 

 A. Antennt fctaceous i Lip entire } and no Tongue. 



ApPENDlGASTER. This fpecies is black ; the abdomen 

 18 petiole, very fhort, and placed on the back of the thorax ; 

 the hind-legs are very long. This is found in divers parts 

 of Europe, Africa, and New Holland. 



* Maculata. Thorax fpotted ; firll fegmcnt of the 

 abdomen with a white dot on each fide ; the fecond is 

 edged with white. It is, as the afterifk denotes, an Englifli 

 infeft. There is a fpecimen of it in fir Jofcph Banks's 

 mufeum. 



Fasciata. Black ; abdomen with two wliite bands, 

 the firft interrupted ; and the tail is white. It is found in 

 different parts of Italy. The thorax is black, covered 

 with filvery down on the fore-part ; the fore-margin is 

 marked with a white hne ; the wings arc white, but tipped 

 with brown. 



S P H 



Sessilis, fo named on account of its (hort, cylindrical, 

 fefTile abdomen. The infeft is black. It inhabiis France ; 

 is very like the S. appendigafter. 



Punctum. This is black ; but the tail is marked with 

 a white dot. It is an Italian infcft. 



NiGRlTiA. This alfo is black ; the upper wings arc 

 marked with a brown band. 



B. /Intennit JUiform ; Lip emarginate ; luith a Rrijlh on each 

 fide ; the Tongue is inJleSed and trifid. 

 Of this feftion there are two fubdivifions ; the one has 

 a petiolate abdomen, that of the other is fefTile. 



a. Abdomen petiolate. 



LuTARlA. Black ; fecond and third fegmcnts of the 

 abdomen rufous ; the lip is filvery. It inhabits Kiel. 



Thom.*:. Black ; abdomen rufous ; the petiole, and 

 fpot on the back, black. It inhabits St. Thomas's ifland. 



Fervens. This is likcwife black ; the abdomen is fer- 

 ruginous ; the wings are brown. It inhabits India. 



Cyanipennis. Villous, blue ; fore-part of the thorax 

 and abdomen grey ; the wings are blue. It inhabits 

 Cayenne, and is large. This is a very beautiful infcdl ; 

 the head is blue ; the mandibles and antennx are black ; 

 the abdomen bluei(h-grey ; the petiole black ; legs black ; 

 the joints yellowifh. 



H.JEM0URHOIDALIS. Black ; lip, tail, and legs, ferru- 

 ginous. Inhabits Africa. A fpecimen is preferved in the 

 mufeum of fir Jofeph Banks. 



Argentea. Glofiy-black ; front villous, filvery; the 

 wings are white, but tipt with brown. It inhabits Coro- 

 mandel, and is a large infeft. 



RuFiPENNis. Black; wings ferruginous, tipt with brown. 

 It inhabits Tranquebar, and is large. 



Flavipennis. Black ; front golden ; abdomen rufous ; 

 the petiole and tips are black. It inhabits Italy. 



Penn&ylvanica. This is of a blackilh hue ; the ab- 

 domen is of a full black ; but the wings are inchning to 3 

 violet. It inhabits America and New Holland. 



ViOLACEA. Blue ; wings white, tipt with brown ; the 

 antenna; are black. It is found at the Cape of Good 

 Hope. 



Cyanea. Blue ; wings azure, tipt with brown ; the 

 antennas are black. It inhabits North America. 



AuRULE.\TA. Head and thorax covered with gold down ; 

 the abdomen is black ; the bafe and legs rufous. It is an 

 inhabitant of Tranquebar. 



ToMENTOSA. The head and thorax of the infe^fts of 

 this fpecies are covered with a gold down ; the abdomen 

 is black ; the bafe and legs are rufous. It inhabits Sierra 

 Leone. 



Femorata. This is blue ; the abdomen is black ; the 

 hind-thighs are rufous. It inhabits Italy. 



Tibialis. Hairy, black-blue; hind-ihanks ferruginous ; 

 wings black. It inhabits the Cape of Good Hope. A 

 fpecimen is preferved in the mufeum of fir Joleph Banks. 



Flavipes. Villous, bhick, with a yellow dot before the 

 wings ; the legs are yellow ; the thighs black. It inhabits 

 America. 



Atr.'V. This is quite black, excepting the lip, wliicli is 

 filvery villous ; wings as long as the abdomen. It ijihabits 

 Italy. 



FiouLUS. Smooth, black ; fcgmcnts of the abdomen at 

 the edges and lip hicid. It inhabiis Upfal, in the holes 

 and crevices of wooden partitions, abandoned bv all other 

 infcde. According to Dr. Shaw, this inletl, when it has 

 found a convenient cavity for the purpofe, fcizes on 3 

 2 fpidcr, 



