ALYSCUM. 



AMBLYSTEGIUM. 



A. roseus. Body papillose. 



BIBL. Koch, Uebersicht, &c. ; Murray, 

 EC. Entom. p. 150 ([tig.). 



ALYSCUM, Duj. A genus of Infusoria, 

 of the family Enchelia, Duj. 



Al. saltans (PI. 30. fig. 8). Colourless, 

 with faint longitudinal furrows ; movement 

 abruptly jerking; length 1-1260 to 1-1000". 



Found in infusion of hay, and river-water, 

 which have been kept. 



Dujardin remarks that it differs from 

 Enchelys nodulosa, Duj. (Pantotricum En- 

 chelys, Ehr.), only in the presence of the 

 retractile cilia. 



BIBL. Dujardin, In/us, p. 391. 



ALYS'SUM, Linn. A genus of Cruci- 

 feree (Flowering Plants), possessing elegant 

 stellate hairs. See HAIBS of plants. 



AM^EEJE'CIUM, or AMAKOU'CIUM, 

 M.-Edw. A genus of Mollusca, of the order 

 Tunicata, and family Botryllidaa. 



Four British species -proliferum (PI. 18. 

 fig. 10), Nordmanni, Argus, and albicans. 



BIBL. M. -Edwards, Mem. s. les Ascid. 

 Comp. ; Forbes and Hanlev, Brit. Mollusca, 

 i. 15 ; Gosse, Mar. Zool. ii. 33. 



AMA'THIA, Larnx. See SERIALABIA. 



AMBER. This substance, found as a 

 mineral, but strongly resembling in appear- 

 ance various gum-resins, is the fossil resin of 

 one or more Coniferous trees belonging to a 

 vegetation now extinct. It is found in drops, 

 lamellae, and stick-shaped pieces, the form 

 and condition depending probably on the 

 mode and situation of its exudation from the 

 trees. In many instances the fragments of 

 amber contain well-preserved remains of the 

 animals and plants which lived at the period 

 of its formation, these having been enclosed 

 by the fluid resin as it escaped from the tree, 

 in a manner which may be exactly compared 

 with our mode of preserving microscopic 

 objects in Canada balsam. Numerous insects, 

 Arachnida, and other animals, with leaves, 

 twigs, fruits, even flowers of plants, have 

 been described and referred satisfactorily to 

 their systematic position; and the aid of the 

 microscope has been largely called in for this 

 purpose, since the elementary structures are 

 in many cases perfectly preserved. The 

 tissue of fragments of Coniferous wood, the 

 stomata of leaves, and glandular and other 

 hairs have been recognized ; and besides the 

 larger Cryptogams, Mosses, Jungermannise, 

 &c., peculiar microscopic Fungi and Diato- 

 niacese have been preserved in a perfectly 

 distinct condition. 



Some of the pieces are cloudy or opaque, 



from the presence of numerous minute 

 cavities, varying in diameter from 1-1000" to 

 1-100,000" "(Sorby). Some of these con- 

 tain gas, some liquid, and others both. 



The structure of the wood of the Amber- 

 fir, Pinites succinifer, Gb'pp., approaches 

 closely that of our Pinus Abies a,ud. P. Picea, 

 differing scarcely in any respect but in the 

 smaller number of the bordered pores, 

 which are of slightly different form. 



Two microscopic Fungi preserved in am- 

 ber have been described and figured by 

 Berkeley : Penicillium curtipes, &u<lllrachy- 

 cladium Thomasinum, a form approaching 

 Corethropis of Corda. A third form, de- 

 scribed at the same time as Streptothrix spi- 

 ralis, he now considers to be an appearance 

 produced by enclosed bubbles of air. 



Ehrenberg detected Diatomacese in am- 

 ber, namely, Amphora gracilis, Cocconeu 

 borealis, Cocconema Cistula, Fragilaria capu- 

 cina, Navicula affinis, N. Amphioxys, N. Ba- 

 cillum, Pinnularia capitata, and P. Gastrum. 

 BIBL. Goppert and Berendt, Regensburg 

 Flora, vol. xxviii. p. 545, 1845 ; Ehrenberg, 

 Ber. Berl.Ak. 1848, p. 17; Berkeley, Moulds 

 in Amber, Ann. N. Hist. 2nd ser. vol. ii. 

 p. 380, tab. xi., xii. ; Idem, Crypt. Bot. 

 p. 303; Sorby and Butler, Mn. Mic. Jn. 

 xvi. p. 225, 1876. 



AMBLY'ODON ,Pal. de Beauv. A genus 

 of Funariaceaa (Acrocarpous Mosses). The 

 only species, A. (Bryum) dealbatum, is rare 

 in Britain. 



BIBL. Miiller, Syn. Muse. i. p. 127; Wil- 

 son, Bryol. Brit. p. 267. 



AMBLYOM'MA, Koch. A genus of 

 Acarina (Arachnida), fam. Ixodea. 



Infests cattle, &c. South America, and 

 Sandwich Islands. 



BIBL. Koch, Arachnid.: Murray, EC. 

 Ent. p. 201 (fig.). 



AMBLY'OPHIS, Ehr. A genus of In- 

 fusoria, of the family Astasiaea. 



Char. Unattached; a single (red) eye- 

 speck; a simple flagelliform filament, no 

 tail. One species. 



A. viridis (PL 30. fig. 55). Green ; length 

 1-210 to 1-140". 



Anterior end of the body colourless, and 

 cleft so as to represent a two-lipped mouth ; 

 nucleus near the middle of the body. 



Several authors regard this as a Euylena. 

 BIBL. Ehr. Infus. p. 103; Dui. Infus. 

 p. 636; Kent, Inf. p. 385. 



AMBLYSTE'GIUM, Br. and Sch. A 

 genus of Mosses included under HYPNUM by 

 Miiller and Wilson. 



