OPEGRAPHA. 



[ 472 ] 



OPHRYDINA. 



with vibratile cilia arranged in regular rows; 

 they contain a so-called nucleus, and exhibit 

 contractile vesicles, but they do not admit 

 colouring matters, nor have they a mouth. 

 In one form, an adhesive suctorial disk has 

 been observed, and in another a hook-appa- 

 ratus, probably serving the same end. They 

 are parasitic within the bodies and usually 

 the intestinal canal of earth-worms, frogs, 

 Planarice, Naides, beneath the gill-plates of 

 Gammarus, &c. 



0. {Bursaria, E.) ranarum, P. & V., is 

 figured in PL 24. fig. 47. 



Dujardin places some of them in his genus 

 Leucophrys. 



BiBL. Purkinje and Valentin, De phen. 

 mot. vibr.; Schutze, Beit. z. Natnrg. d. Tur- 

 bell.; Stein, Infus. p. 178, &c. 



OPEGRAPHA, Ach.— A genus of Gra- 

 phideae (Gymnocarpous Lichens), growing 

 on bark of trees, stones, &c. Besides their 

 linear lirellcB, the fronds bear spermagonia. in 

 0. varia and 0. calcarea, forming black spots 

 on the surface, communicating with little 

 unilocular cavities lined with short, linear 

 sterigmata bearing numerous spermatia. 

 Mr. Leighton enumerates fourteen species 

 and numerous varieties in his recent mono- 

 graph. 



BiBL. Bn7. Hor. ii. pt. 1. p. 147; Leigh- 

 ton, Jww. Nat. Hist. 2ndser. xiii.; Tulasne, 

 Ann. des Sc. nat. 3 ser. xvii. p. 207. 



OPERCULARIA, Goldfuss.— A genus of 

 Infusoria, of the family Vorticellina. 



According to Ehrenberg's description, 

 Opercularia resembles Epistylis in being 

 furnished with a rigid (not contractile), 

 branched stalk, but differs in the presence 

 of two kinds of bodies, larger and smaller, 

 attached to the branches, the former being 

 usually situated in the axils. Stein regards 

 the larger bodies as belonging to individuals 

 of an older generation, which attach them- 

 selves to the branches as to other foreign 

 bodies, and there secrete a new polypidom. 

 This author would distinguish Opercularia 

 by the circular anterior margin or rim (peri- 

 stome) of the body not being thickened and 

 everted, by no cilia arising from it, and by 

 the presence of a kind of lower lip, formed 

 of a delicate everted fold. 



Adapted to the peristome in both genera 

 is a conical plug-like retractile body, fringed 

 with cilia, and flat or convex at the end. 



O. articulata, E. Found adherent to Hy- 

 dropltilus piceus and Dytiscus marginalis . 

 PI. 25. fig. 25, Acineta-^t'A^Q (Infuso- 

 ria). 



0. berherina, St. Found upon Noterus 

 crassicornis, a water-beetle. 



BiBL. Ehrenberg, /?i/m5. p. 286 ; Stein, 

 Infus. passim. 



OPHIDOMONAS,Ehr.— A generic name 

 applied to slender, filiform, spiral (helical), 

 vibrio-\\]s.e. bodies, of a brown or red colour, 

 mth obtuse ends, and actively moving through 

 the water by means of an anterior flagelliform 

 filament. Ehrenberg places them among 

 the Infusoria, in the family Cryptomonadina, 

 and admits two species, characterized by the 

 diff'erence in colour. One was found in 

 fresh, the other in brackish water. Length 

 about 1-570", breadth 1-9000". In some 

 the spire forms only half a turn, in others 

 two and a half turns. 



Probably an Alga. Is it the young state 

 of Spirulina ? 



BiBL. Ehrenberg, Infus. p. 43, and Ber. 

 d. Berl. Akad. 1840. 



OPHIOGLOSSACE.E. — A family of 

 Ferns, distinguished from all others by the 

 characters both of the vegetative and repro- 

 ductive structures. The fronds are always 

 divided into two parts, one foliaceous and 

 sterile, and the other fertile, neither being 

 ever rolled up in the form of a cross. The 

 sporanges are destitute of any trace of an 

 annulus, and always split very regularly to 

 discharge the spores. 



Synopsis of Genera. 



1. Ophioglossum. Sporanges dehiscing 

 transversely, connate on an undivided disti- 

 chous spike. 



II. BoTRYCHiuM. Sporanges dehiscing 

 transversely, arranged on a distichous, se- 

 cond, bi-, tri-pinnate spike. 



III. Helminthostachys. Sporanges 

 dehiscing externally, vertically from the base 

 to the middle, collected in whorls, with 

 crest-like appendages and stalked, arranged 

 distichouslv on an elongated spike. 



OPHIOGLOSSUM, Linn.— The typical 

 genus of Ophioglossaceous Ferns, repre- 

 sented by the Adder's-tongue Fern, Ophio- 

 glossum vulgatum. 



OPHRYDINA, Ehr.— A family of Infu- 

 soria, corresponding to Vorticellina with a 

 carapace (p. 348). 



Animals grouped in a gelatinous mass. . . . 



TBody attached to the bottom i 

 Animals^ of the carapace by a stalk / 

 single I Body not f Carapace stalked . . 



V. stalked \ Carapace sessile . . 



Ophrydium. 



Tintinnus. 



. Cothurniu. 

 . Vaginicvlu. 



BiRL. Ehrenberg, Infus. p. 291. 



