ASPIDISCINA. 



[ 82 ] 



ASTASIA. 



BIBL. Ehrenb. Infus.; Duj. In/us.-, 

 Stein, Infusionsthiere &c. 



ASPIDISCI'NA, Ehr. A family of In- 

 fusoria. 



Char. A carapace present in the form of 

 a transparent flattened shield, projecting 

 beyond the mouth in front; flexible bristles 

 on the ventral surface of the body, with 

 delicate oral cilia. 



Ehrenberg describes an alimentary canal, 

 the inferior orifice of which alone is terminal. 

 Hence they correspond to Euplotes, with 

 the excrementitial orifice terminal. 



Dujardin places them among his Coccu- 



The setae, styles, or cirri serve for climb- 

 ing, whilst by the cilia the animals are 

 enabled to swim. 



This family should not be retained, but 

 the single genus of which it is constituted, 

 Aspidisca, referred to the Euplota. 



ASPID'IUM, Schott. A genus of Aspi- 



Fig. 47. 



Aspidium trifoliatum. 

 An indusium covering a sorus. 



diese (Polypodiaceous Ferns), in its old 

 sense including many of our native species, 



Fig. 48. 



Aspidium trifoliatum. 



Side view, cut through perpendicularly. 



Magnified 25 diameters. 



but now broken up into subdivisions, raised 

 to the rank of genera. 



A. Lonchitis and aculeatum, including loba- 

 tum and angulare as varieties, are British. 



ASPLANCH'NA, Gosse. A genus of 

 Rotatoria, of the family Hydatingea. 



Char. Foot, intestine, and anus absent ; 

 eye-spots (1 to 3) and mandibles present ; 

 sexes 



A. Brightwellii (Notommata syrinx, Ehr. ?). 



Female : jaws with a single tooth ; eye- 

 spot single ; tremulous bodies attached to 

 an extended filament ; aquatic ; length 1- 

 24". Male : jaws, pharynx, and stomach 

 absent ; body truncate ; length 1-40". 



A. priodonta (PI. 43. fig. 7, female). 3 

 eye-spots ; tremulous bodies attached to a 

 tortuous filament; aquatic ; length female 

 1-48", male 1-110" ; jaws of female serrated 

 (7ft). 



BIBL. Brightwell, Ann. N. H. ser. 2, ii. 

 p. 153, pi. 6 ; Dalrymple, Tr. Roy. Soc. 

 1849, and Ann. N. H. 1849, iii. p. 618 ; 

 Gosse, Ann. N. H. 1850, vi. p. 18, viii. 

 p. 197. 



ASPLENIE'^E. A family of Polypo- 

 diaceous Ferns, with indusiate sori. Ge- 

 nera : 



Asplenium. Sori dorsal or submarginal, 

 linear or oblong : indusium similar in shape, 

 straight or curved, single or double, plane 

 or tumid, bursting along the outer edge. 



Allantodia. Sori dorsal, linear-oblong, 

 attached to the primary veins ; indusium of 

 the same shape, and entirely enclosing them, 

 bursting in an irregular line down to the 

 centre. 



Actiniopteris. Sori linear elongate, sub- 

 marginal; indusium of the same shape, 

 folded over them, placed one on each side 

 of the narrow segments of the frond, and 

 opening towards the midrib. Frond flabel- 

 late. 

 ; BIBL. See FERNS. 



ASPLE'NIUM, Presl, Spken-iuort.A. 

 well-known genus of Asplenieee (Polypodi- 

 aceous Ferns), containing a number of indi- 

 genous species. 



ASSILI'NA, D'Orb. A variety ofNum- 

 mulina (grouped as a subgenus), in which 

 the alar lobes are reduced to a minimum, 

 and thereby the faces of the shell are left un- 

 thickened, except perhaps at their centres ; 

 and nearly or quite all the whorls are ex- 

 posed. These shells are the NummuKwK 

 explanatce of D'Archiac and Haime. Assi- 

 lina exponent, Sow., sp., is the best type of 

 this subgenus of Nummulina. It abounds, 

 with the more perfect type, in the older 

 Tertiary strata of Switzerland and India. 



BIBL. D'Orbigny, Ann. Sc. Nat. vii. 296 

 (the Modele 88 here referred to, however, 

 is an Operculina) ; D'Archiac and J. Haime, 

 Foss. Ann. de llnde-, Parker and Jones, 

 Ann. N. H. ser. 3, v. 110, and viii. 232. 



ASTA'SIA, Ehr. A genus of Infusoria 

 of the family Astasisea. 



Char. Unattached, no eye-spot. Flagel- 



