OF THE ACINETINA. 



oijo 



Polypes. This is called a Podoplirya 

 by Lachinann. Length, including- stalk, 

 lll70" to 1-100". 



A. tuber osa (Vorticella ticbcrosa, M.) 

 (xxvi. 3-4). — Triangidar, compressed ; 

 dilated and truncate anteriorly, with 

 three obtuse tubercles or horns, of which 

 the two lateral are more constant, and 

 furnished with tentacula. Pedicle simple 

 and slender. 1-210" to 1-100". In marsh- 

 aud sea- water ; on Ceramium diaphamim 

 (XXI. 3-4). See account of Acinda of 

 ZootJiamnium ajfine. 



A. mystacina (x. 205). — Subglobose, 

 obtusely horned, with two elongated 

 bundles of tentacida: pedicle slender. 

 Upon Lemna minor. 1-800" to 1-120". 



A. Ferrum-cquinum (xxiii. 26, 27). — 

 Oyate, white, tentacula disposed at its 

 front; pedicle small, thick; a central 

 gland ofa horse-shoe shape. 1-240". Ber- 

 lin. This Lachmann calls a Podoplirya. 



A. (?). — Brightwell describes an ani- 

 malcule with an oyal sheath, of a dark 

 colour, opake and granulated, and having 

 a bundle of diverging rays proceeding 

 from each extremity, many of which, by 

 conti'action or otherwise, have a globular 

 tip. They were not observed to move or 

 catch other animalcules. In fresh water 

 at Oulton, Norfolk. 



A. patula. — A species mentioned by 

 Lachmann {A. S. N. 1857) as developing 

 embryos, and common on Algte and 

 Zoster a found on the coast of Norway. 



A. Cucullus. — Another species named, 

 and not described, by the same naturalist. 

 Foimd in the Fj ord of Bergen. 



A. cylindrica (Perty). — Colourless, 

 transparent, cylindrical, supported on a 

 short stem. 1-22"'. 



CotJiurma maritima. — Its presumed 

 Acineta bore a close resemblance to Ad- 

 nata tuberosa (Ehr.). It had a moderately 

 long, thin stalk, not dilated upwards ; and 

 the body was enclosed by a hyaline cap- 

 sule, capped by a conical, roof-like por- 

 tion, from which the inverted conical or 

 pyriform granular body was suspended, 

 more or less space intervening between 

 it and the capsule. From each external 

 anterior an^le proceeded a bundle of 

 gently-tapering, line, and slightly capi- 

 tate tentacles, retractile and divergent. 

 Internally was a round contractile space 

 and an oval nucleus, 



Epktylis branchhphila. — The Acineta 

 assigned to it by Stein has usually a short, 

 slightly cuned, stiff and solid pedicle, 

 always much thinner than the stem of 

 the fyistylis itself. Figure pyriform ; two 

 bundles of bristly, non-capitate tentacula 



given off from its anterior end. The body 

 exhibits constant changes in outline by 

 the vermicidar contractions of its tissue, 

 and likewise alters its relative position 

 with its stem. It likewise exhibits trans- 

 itory folds, swellings, and inflations of 

 the surface. 1-240". 



E. crassicolUs. — Stem of its Aci?ieta 

 transversely striped, crystalline, mostly 

 straight, and generally like that of the 

 Epistylis itself, except in thickness, being 

 in this respect much thinner, save at its 

 expansion, supporting the body of the 

 Acineta. This last is of a rectangular 

 iigure, with rounded angles, and often 

 inflated at the middle. Tentacula taper- 

 ing, capitate, always few in number — 

 from two to four at each of the four 

 angles, and always longer than the dia- 

 meter of the body. Length (maximum ) 

 of body^l-30"', breadth 1-28"'. Found 

 on the Entomostraca. 



E. plicatilis. — Acineta-'^e&\c\Q solid, 

 longitudinally striated, much narrower 

 than stem of the Epistylis, except at its 

 upward dilatation, where the body was 

 affixed. Body pyriform or ovoid, com- 

 pressed ; in most specimens with a 

 smooth surface and no tentacida : when 

 the last were present they were small, 

 capitate, and few in numlDer, and col- 

 lected in four bundles, one on each lobu- 

 lar expansion of the then expanded Aci- 

 neta. Maxim, length 1-16'", width 1-20'". 



Opercularia articulata (xxx. 3-4). — 

 Pedicle of Acineta rigid, solid, thin, 

 mostly curved, and shorter than the 

 body. After a certain height (about 

 the half) it suddenl}^ and gTeatly ex- 

 pands to its point of articulation wdth 

 the body. It is striated longitudinally, 

 and hyaline. Body compressed, with a 

 circular outline, or discoid, ovoid, or py- 

 riform figure. Abruptly and widely trun- 

 cate at its base, where it is fixed on its 

 pedicle : siu-romided by an apparently 

 firm and thick integument, without 

 aperture, and covered at slight intervals 

 by short, thick, tubular and undulating- 

 tentacles. Maximum length 1-20'" to 

 1-12'", width 1-14'" to 1-24'". 



O. berberina (xxiii. 17-20). — Stem of 

 Acineta very short, thick, solid, smooth 

 or transversely striped, usually- con- 

 tracted in the centre and dilated at each 

 end. The stem supports a very large, 

 flattened, discoid capside, with a para- 

 bolic outline, and having- a gently curved 

 anterior double margin enclosing- an open 

 space. The margins are comparable to 

 a front and back lip : the walls of the 

 capsule thick, flexible, and hyaline. A 



