FUSIDIUM. 



[ 347 ] 



GAMASEA. 



Fig. 266. 



FUSED 'IUM, Lk. A genus of Mucedines 

 (Hyphomycetous Fungi), characterized by 

 very delicate white or coloured flocci, which 

 do not form a moist or gelatinous mass as 

 in Fusisporium, and are very evanescent. 

 Spores straight, filiform. The species grow 

 on dead leaves, forming a thin powdery 

 stratum. 



BIBL. Berk. Outl 357; Cooke, Br.Fung. 

 609; GreviUe, Crypt. Fl. pi. 102. 



FUSISPO'RIUM, Lk. A genus of Sepe- 

 doniei (Hyphomycetous Fungi), growing 

 upon vegetable substances often when de- 

 caying, characterized by elon- 

 gate fusiform curved septate 

 spores (fig. 266), which ul- 

 timately form a gelatinous 

 mass, the flocci being in ge- 

 neral more or less obscure, or 

 if present very delicate, the 

 spores in fact forming the 

 principal element. s ume- 

 rous species are recorded as 

 British. F. atrovirens is de- Spores. Magn. 

 structive to onions. F. beta m dMB * 

 common on decaying mangold- wurzel. F. 

 fceni sometimes runs over the cut surface of 

 a havstack, forming broad orange-red patches. 



BIBL. Berk. Hook. Br. FL ii. pt. 2. 251, 

 Ann. N. H. vi. 438, pi. 14. fig. 28 ; 2 ser. vii. 

 178 ; Fries, Syst. Myc. iii. 442, Sum. Veget. 

 473 ; Greville,c. Crypt. Fl. pi. 102. figs. 1 & 2. 



FU SULI'NA, Fisch. A genus of spiral, 

 hyaline Foraminifera, near Nonionina and 

 Nummulina, but fusiform instead of nauti- 

 loid, the umbilical axis of the shell being 

 much extended. The lateral tapering elon- 

 gations of the chambers in some cases are 

 simple, yielding symmetrical casts figured 

 by Ehrenberg as Borelis in the ' Mikro- 

 geologie ; ' but in others the chambers are 

 divided throughout by labyrinthic segmen- 

 tation, giving more complex casts and sec- 

 tions. 



F. cylindrica (PI. 24. f . 15) and its va- 

 rieties form enormous masses of limestone 

 in the Carboniferous system, in Russia and 

 North America. 



BIBL. Carpenter, Foram. 304; M. Mic. 

 Jn. 1870, 180 ; Parker and Jones, Ann. 

 N. H. 1872, 260; Brady, ibid. 1876,414; 

 Holier, Foram. Russ. 1878. 



G. 



GALLIONEL'LA, Bory, = MELOSIRA, 

 Agardh. 



GALLS. These are abnormal growths, 

 tumours as they might be called, produced 



upon or in vegetables by the action of ani- 

 mals, especially insects of the order Hyme- 

 noptera. They were supposed to arise from 

 the irritation caused by a poisonous liquid 

 discharged into the orifice made by the 

 insect for the introduction of its egg. At 

 all events a convergence of the nutritive 

 juices towards the wound takes place, 

 whence results a kind of hypertrophy of the 

 tissues, and frequently the accumulation of 

 such substances as starch in the cells. The 

 forms may be regular or irregular ; most of 

 them are characteristic, as, for example, 

 the well-known nut-gall, the oak-apple, 

 the bedeguar of the rose, &c. Both cellular 

 and vascular structures contribute to form 

 the substance of galls. We cannot enter 

 into their minute structure here, but refer 

 to an elaborate paper by Dr. Lacaze-Du- 

 thiers and to Adler's more recent memoir. 

 Adler's plates will enable the identification 

 of most, if not all, the British oak-galls, 

 and will perhaps lead to the discovery of 

 others. See APHIDJE, CYNIPIDJE, and 

 PHYTOPTID^J. 



BIBL. Lacaze-Duthiers, Ann. Sc. Nat. 

 3 ser. xix. 273, where also the earlier lite- 

 rature is given ; Adler, Zeitschr. wiss. Zool. 

 liii. 151 ; M'Lachlan, Ent. Mn. Mag. 1881, 

 xvii. 259. 



GALUM'NA, Heyden, Gervais. A ge- 

 nus of Arachnida, of the order Acarina, and 

 family Oribatea. 



Char. Abdomen subglobular, depressed; 

 sides of the pseudo-thorax forming a salient 

 or wing-like angle ; legs of moderate length. 



This genus approximates to Belba. 



The three species, the bodies of which 

 are of a blackish, blackish-chestnut, or ash 

 colour, are found on mosses. 



BIBL. Walckenaer, Arachn. (Gervais) ; 

 Hermann, Mem. Apter. 91 ; Koch, Deutsch. 

 Crustac. &c. 



GAMA'SEA. A family of Arachnida, 

 of the order Acarina. 



Characterized by the free filiform palpi, 

 the chelate mandibles, and the 7- jointed 

 legs with two claws and a caruncle. ' Gene- 

 rally parasitic, and found on insects and 

 birds; some upon fishes, reptiles, and 

 mammals ; eyeless. 



Dermanyssm. Body soft; last joint of 

 palpi smallest ; labium acute ; mandibles 

 of male, chelate, outer claw very long, of 

 female, ensiform ; legs with two claws and 

 a caruncle, anterior longest, coxae approxi- 

 mate. On birds and bats (PI. 6. fig. 24). 



Gamasus. Body hard; labium trifidj 



