GEiXUS ACIXETA. 833 



and had evidently become detached from its original basis of support. The external 

 surface of the lorica was observed to be densely and finely hispid, but they were 

 unable to determine whether this feature was due to the presence of some foreign 

 growth or an essential part of the organism. The single specimen examined enclosed 

 six germs, one of which was seen to escape as a free-swimming pear-shaped embryo, 

 bearing several circlets of cilia at its more attenuate posterior extremity, and 

 being devoid of all trace at that time of the tentacula of the adult form. 



Acineta notonectse, C. & L. Pl. XLVI. Fig. 44. 



Lorica subcylindrical, tubular, gradually tapering towards the posterior 

 extremity, the anterior margin somewhat oblique ; pedicle absent or rudi- 

 mentary ; body adherent to the lorica, and occupying its entire cavity ; 

 tentacle distinctly capitate, forming two fascicles at the anterior extremity ; 

 endoplast oval. Length of lorica 1-150". 



Hab. — Fresh water, on Notonecta glauca. 



The rudimentary condition of the pedicle in this species, the lorica being mostly 

 adherent only by its more attenuate posterior extremity, would seem to almost 

 justify its transfer to the genus Solenophrya. 



Acineta compressa, C. & L. 



Lorica shortly cup-shaped, as broad as long, exceedingly compressed, 

 the antero-lateral angles obliquely truncate; pedicle long, slender and 

 straight, having a short nodular thickening at its point of junction with the 

 lorica, but below this entirely even ; body nearly filling the lorica, freely 

 suspended within the same, bearing two antero-lateral fascicles of capitate 

 tentacles; contractile vesicle single. Length of lorica 1-275". 



Hab. — Salt water : Norwegian coast (C. & L.). 



Acineta poculum, Hertwig. 



Lorica obconical, or wineglass-shaped, nearly as broad as long, widest 

 at the antero-border, and tapering gradually towards its point of junction 

 with the pedicle; body scarcely occupying the anterior half of the cavity 

 of the lorica ; tentacles distinctly capitate at their distal terminations, 

 forming two antero-lateral fascicles, the proximal or intra-parenchymal 

 terminations of which interlace with one another along the posterior 

 margin of the body ; pedicle slender, not constricted at its point of junction 

 with the lorica ; endoplast subspherical. Dimensions unrecorded. 



Hab. — Salt water. 



The lorica of this type, excepting for the absence of the narrow constriction at 

 its point of juncture with the pedicle, is apparently closely identical with that of 

 Acineta paiula. The fasciculate distribution of the tentacula, however, afibrds an 

 additional means of distinguishing it from that species. 



Acineta cothumia, C. & L. 



Lorica wineglass-shaped, rounded posteriorly, the anterior margin 

 obliquely bevelled, and split into four or five triangular valve-like segments 

 as in A. mystacina, mounted on a short slender pedicle; body freely sus- 



VOL. II. 2 B 



