832 ORDER TENTACULIFERA-SUCTORIA. 



two antero-lateral fascicles of capitate tentacula ; contractile vesicles 

 numerous, situated near the anterior border ; endoplast band-like, sinuous. 

 Length 1-150". HAB. Fresh water, on aquatic Coleoptera. 



This species was originally described by Stein as an Acinete condition of Opercu- 

 laria berberina, but subsequently received from Claparede and Lachmann the title as 

 above given. A yet later name proposed by Stein is that of Acineta ligulata. The 

 embryos of this type, as figured by the last-named authority, see PL XL VI. Fig. 39, 

 are flattened, and holotrichously ciliate. 



Acineta fcetida, Maupas. PL. XLVIII. FIGS. 13-17. 



Lorica compressed, subtriangular, the anterior border widest, gradually 

 diminishing towards the usually obtusely pointed posterior extremity, the 

 surface of the lorica frequently evenly plicate in an oblique direction, the 

 anterior border closed in excepting for the presence of a narrow slit-like 

 opening, supplemented at the two lateral angles by a larger ovate aperture 

 for the passage of the tentacles ; body almost completely filling the cavity 

 of the lorica ; the tentacles distinctly capitate, disposed in two antero- 

 lateral fascicles which protrude through the corresponding apertures in the 

 lorica ; pedicle short and rudimentary, usually eccentric ; contractile 

 vesicle single, occupying an antero-lateral position ; endoplast elongate- 

 ovate, subcentral, with a minute laterally attached endoplastule. Length 

 of lorica 1-600". HAB. Salt water, among decaying seaweeds. 



The general contour of this species very closely resembles that of the fresh-water 

 form Acineta linguifera previously described, but may, in addition to its distinct 

 habitat, be distinguished from that type by the relatively close application of the 

 front walls of the lorica, these, in that last-named species, being everted to such an 

 extent as to admit of the protrusion of the body, in addition to the tentacles, beyond 

 their edges. In the conformation of the internally developed embryos there is like- 

 wise a most remarkable divergence, for, while in A. linguifera, as observed by Stein, 

 they are flattened and holotrichously ciliate, in the present type, as figured and 

 described by E. Maupas, they are elongate-ovate or pyriform, with five obliquely 

 distinct or continuous spiral ciliate grooves, which communicate to them a singular 

 helicoidal contour. As many as four represented the common number of these 

 embryos developed in the brood-cavity of the parent, while in its apparently near 

 ally, Acineta linguifera, the embryos are usually produced singly. The earlier 

 phases following upon the attachment of the embryos and their development towards 

 the adult form in Acineta fcetida, are remarkable from the fact that the lorica in no 

 way resembles that of the parent, being quite smooth, as broad or broader than long, 

 and, excepting for the circumstance that the tentacles have a fasciculate arrangement, 

 might easily be mistaken for that of Acineta emaciata described further on. 



Acineta cucullus, C. & L. 



Lorica infundibulate or obconical, tapering posteriorly, one side of the 

 anterior margin deeply emarginate ; pedicle long and slender, even through- 

 out ; body freely suspended within the lorica, protruding but little from its 

 orifice, bearing two fascicles of suctorial tubes. Length of lorica i-ioo". 



HAB. Salt water. 



The single example upon which Claparede and Lachmann have instituted this 

 species was captured by them floating in the sea in the neighbourhood of Bergen, 



