558 DESCEIPTION OF {^olycjostrica. 



with two eloBgated bundles of tentacula ; pedicle slender, fig. 205 . 

 Found upon Lemua minor. Length of entire body 1 -860th 

 to l-120th. 



AciNETA ferrum equinum. — Body ovate, white, tentacula disposed at 

 its front ; pedicle small, thick ; a central gland of a horse-shoe shape. 

 Size 1 -240th. Berlin. 



A. (?) — Brightwell describes an animalcule with an oval sheath, 

 of a dai'k colour, opaque and granulated, and having a bundle of 

 diverging rays proceeding from each extremity, many of which, by 

 contraction or otherwise, have a globular tip. They were not ob- 

 served to move or catch other animalcules. Found in fr'esh-water at 

 Oulton, Norfolk. 



Genus Dendkosoma.. — This includes beings which resemble Aeti- 

 nopJirys, supported on a branching pedicle. The base of the thick 

 pedicle or ti'unk is fixed, and its divisions bear at their extremities 

 the animalcules. In appearance, therefore, it resembles a micro- 

 scopical Sertularian polype. 



D. radians. — Corpuscles (animacules) conical, dense ; on soft, 

 smooth, and alternately disposed branches; and furnished with 

 tentacula. 



Genus Alderta. — Mr. Alder has described and figured (Ann. Nat. 

 Hist. vol. vii, 1851, p. 427) three new species of Infusoria, which 

 he esteems to be most akin to Acineta. Unfortunately for any 

 systematic arrangement, he has contrived no names for them ; if we 

 might be allowed, we would suggest the generic appellation Axdekia, 

 in honour of the discoverer. 



The follo"WTng characteristics arc condensed from Mr. Alder's 

 account, and, for convenience sake, we have ventured upon specific 

 or trivial names, for the three species indicated. 



A. apiculosa. — Body vase — or cup — form, expanded at the top, and 

 set round with numerous pointed tentacles, abruptly thickened to- 

 wards the base, and forming more than one row ; they had vciy 

 little motion, but were occasionally bent forwai-ds, and the whole 

 were sometimes slowly retracted. The body was attached by a 

 tolerably stout stem. Found parasitic on Sertularia. 



A. ovala. — Body o\'ate, with a very slender and short stem ; ten- 



