ANGUILLULID^. 



[ 43 ] 



ANGULAR APERTURE, 



long as broad in the adult state ; length 

 1-42 to 1-4"; pharynx with an exsertile 

 epear, trilobed at the base. 



Found in blighted wheat, and sometimes 

 infesting the young plants, burrowing in the 

 leaf-sheaths, where we have found them re- 

 producing by ova, in great numbers. 



Aiiff. gluiinis. About 20 times as long 

 as broad, terminating posteriorly in a fine 

 elongated point; length l-lo". 



Found in sour paste. 



Other so-called AmjuilMcs are found in 

 the same situations as A. Jluviatilis, See 

 Enoplid^. 



Aug. {Leptode7-d) stercoralis is a simple, 

 smooth-bodied nematode 1-G25" long; 

 somewhat narrowed in front, and more so 

 behind ; the males and females being nearly 

 equal in size. Found in enormous num- 

 bers in the evacuations of patients in Cochin- 

 China. 



Ang. {Lept.') intestinalis is a larger spe- 

 cies, sometimes found with the above, but 

 less numerous; length 1-11", breadth 

 l-7o7;'. 



It is almost impossible to dissect these 

 minute beings in the ordinary manner ; the 

 best method of proceeding is to wound the 

 body, and gently press out the contents 

 under water. 



BiBL. Duges, Ann. Sc. Nat. 1826, ix. ; 

 Bauer, PJiil. Tr. 182.3 ; Ehrenberg, Symhol. 

 Phys.; Dujardin, Helminthes \ Davaine, 

 Ann. N. H. 18o6, xviii. p. 2(38; Bavay, 

 ibid. 1877, xix. p. 350 ; Kiihn, Sieb. & K61- 

 liker's Zeitsch. 1857, p. 129; Bastian, Linn. 

 Tr. 1805, XXV. 73; Cobbold, Entozoa, 1879, 

 p. 236 (figs.). 



ANGUILLU'LID^.— A family of ne- 

 matoid worms. 



This family corresponds pretty nearly to 

 the Enoplidse of Dujardin. The genera 

 have been re\'ised by Bastian in an excel- 

 lent monogTaph, in which several new 

 genera and 100 new species are described 

 and figured; to which we must refer those 

 who are specially interested in this curious 

 group. 



A small nematoid is very destructive to 

 young cucumber plants, forming cysts in 

 the roots. M. Cornu has recorded a similar 

 disease in the Rubiacefe. The genus to 

 which these nematoids belong has not been 

 determined. 



BiBL. Bastian, ZmM.r;'.xxv.p.73, 1865; 

 Cornu, Compt. rendus, 1878-9 ; Beauregard, 

 Mic. 1880, p. 604. 



ANGUINA'RIA,Lamk.(^ETEA, Lamx.). 



— A genus ofmarinePolyzoa,ofthe suborder 

 Cheilostomata, and family Kucratiida^. 



Char. Cellstubular, erect, scat tered,rising 

 from a creeping fistular fibre adnate to a 

 foreign base; aperture terminal or subter- 

 minal. British species : — 



A. Sj)afulata. Cells spatulate at the end, 

 curved, ringed. 



A. recta. Cells straight. 



A. triincata. Cells truncate at the end, 

 surface punctate, not ringed. 



Fom- foreign species. 



BiBL. Johnston, Br. Zooph. 292 ; Gosse, 

 Mar. Zool. ii. 13 ; Busk, Cat. Mar. Pohjz. 

 31 ; Hincks, Polyz. 1880, p. 2. 



ANGUINEL'LA, V. Bened.— Agenus of 

 marine Poh'zoa, of the suborder Ctenosto- 

 mata, and family Vesiculariidse. 



A. puhnata. Palmately branched, largely 

 composed of mud; tentacles 12; no gizzard; 

 British. 



BiBL. Gosse, Mar. Zool. ii. 22 ; Van 

 Beneden, Bryoz.; Hincks, Mar. Polyz. 1880, 

 p. 539. 



ANGULAR APERTURE.— The angu- 

 lar aperture of an object-glass is the angle 

 measured by the arc of a circle, the centre 

 of which is formed by the focal point of the 

 object-glass, the radii being formed by the 

 most extreme lateral rays which the object- 

 glass admits. 



Thus let fig. 16 represent a perpendicular 

 section of the lowest combination of an 

 object-glass of small aperture : a is the 



Fig. 16. 



Fiff. 17. 



angle of aperture ; and /, e are the most 

 oblique I'ays which the object-glass will 

 admit ; the angle is measured by the dotted 

 arc b. In the object-glass of larger aper- 

 ture, fig. 17, the arc b which measures the 

 angle is much larger, and the radii repre- 

 senting the extreme lateral rays are much 

 more oblique. Hence it is evident that the 

 object-glass of larger aperture admits all 



