ALSOPHILA. 



[ 32 ] 



ALYCUS, 



The three British species may be thus 



distinguished : — 



, r Shell reticulated reticulata*. 



' I Shell striated or grooved 2. 



/"Anterior margin of shell nearly 



2 J straight, shell brown quadrangularis] . 



J Anterior margin of shell convex, 



(. shell colourless ovata. 



* PI. 19. fig. 4. t PI. 19. fig. 5. 



BiBL. Baird, Brit. Eiitomost. p. 131 j 

 pi. 16. 



ALSOPH'ILA, E. Fig. 8. 



Brown. — A gejuis of 

 PolypodiaceousFerns. -^' 



Exotic (fig. 8). 



Char. Sorighihose, /; ;>;ji.7:;«s:f^> 



dorsal, on a vein or in M\ 



the fork of a vein. »» 

 Receptacle mostly f^kj/m 

 elevated, often vil- j^^W^"^^ 

 Ions. Involucre ab- <'Mht'im 

 sent. Veins simple Alsophiia excelsa. 



or furcate, free. Pinnule with sori. 



Arborescent, mostly tropical; species 

 numerous. 



Sections of their petioles exhibit fine scala- 

 riforni ducts, the slits between the fibres 

 forming many perpendicular rows. 



BiBL. Hooker & Baker, Sxjn. FlHc.-p. 31. 



ALTERNA'llIA, Nees.— A 

 genus of Torulacei (Coniomyce- Fig. 9. 

 tons Fungi). Microscopic fila- 

 mentous Fungi, remarkable for 

 their flask-shaped, cellular spores, 

 produced in cliaius which ulti- 

 mately break up into the single 

 links (fig. 9). 



A. tenuis grows parasitically fj^i^ (,^3 

 upon other filamentous Fungi, 

 and on decaying gourds, and is 

 common about Berlin, Prague, -^A !ol 

 and other places. Corda made 

 the ripe spores germinate on Cla- A ij 

 dosporimn herharum kept moist. '*■"' 

 They usually first protruded a 

 filament from the neck or atte- 

 nuated projection, and afterwards 

 others from the cells at the sides 

 and opposite end of the spore. Alternaria 

 These tilaments became branched, p ",."[][■> 



The Messrs. Tulasne have spon-boar- 

 shown that Alternaria tenuis is '/Jj*] 'i'"'''^'^"'' 

 merely a state of the common magnified). 

 Sphccria herharuin, 



BiBL. C(n-(la, Ic. Fuihj. iii. p. 5, pi. 1. 

 fig. 16; Pracliljl. eHr<>2K iSeliiu))nelhil(l .y\. 13; 

 Tulasne, Fung. Carpoloyia, ii. pi. 32, 



ALTEPtNATION of Genekations. 



See Generations. 



ALTEUTHA, Baird (PeUidiujn, Brady). 

 — A genus of marine Entomostraca, of the 

 order Copepoda, and family Cyclopidte. 



A. depressa (PI. 19. fig. 3). Eye red. 

 Found in Berwick Bay, but not common. 



A. i7iterrtipta, common ; A. crenatula. 



BiBL. Baird, Brit. Fatom. p. 216; Brady, 

 Copepoda (Ray Soc), ii. p. 158. 



AL'TICA. See Haltica. 



ALU'CITA. — A genus of Lepidopterous 

 insects, of the family Alucitidfe. 



The species are remarkable from having 

 the wings divided into six lobes or rays 

 which are fringed with long narrow scales 

 resembling hairs, giving them a beautiful 

 feathery appearance. They are not imcom- 

 mon in gardens, and sometimes enter out- 

 houses. 



The species of Pterojjhorus exhibit the 

 same structure, except that the anterior 

 wings have two, and the posterior three lobes. 



BiBL. See Insects (Wings). 



ALUM. — This well-known substancecon- 

 sists chemically of potash and alumina, ^vitll 

 sulphuric acid and water. Itscry-stals belong 

 to the regular cubic or tesseral sy-stem, and 

 usually' assume the octahedral form. When 

 dissolved in boiling water with slaked linie, 

 it crystallizes in cubes. The term alum lias 

 recently been extended to those compounds 

 in which the potash is replaced by other 

 bases ; thus we have ammonia-alum, 

 chrome-alum, &c. The crystals exert no 

 influence upon polarized light. Common 

 alum possesses but little microscopic 

 interest. Its solution is used in some of 

 the preservative liquids. 



AL VEOLINA, D'Orb.— A genus of Fora- 

 miniferaImperforata,of the family Miliolida 

 (Carpenter), nearly allied to Orbiculina, but 

 elongated in the direction of the axis ; Or- 

 biculina being greatly compressed in this di- 

 rection. Alveolina rotella (D'Orb., sp.), how- 

 ever, is nautiloid ; Al. melo, var. a, Ficht. 

 and MoU, is oblately spheioidal : var. ^, 

 prolately' spheroidal; Al. ovoidca, D.'Orh., 

 elongate-oval ; Al. sahulosa, Montft., fu^^i- 

 form ; and Al. elonyata, l)'Orb., is sub- 

 cylindrical. 



A. fuslformis (pi. 23. fig. 15) ; A. rotella 

 (pi. 23. fi'g^. 16). 



Buii.. CJarpenter, riiil. Trans. 1850, p, 

 552 ; Foram. p. 99 ; Parker and Jones, 

 A72n. Nat. Hist. ser. 3. viii. p. 161. 



AL'YCUS, Koch. — A genus of Acarina, 

 fam. Trombidiua. 



