572 ORDER HOLOTRICHA. 



prehensile apparatus corneous, hammer-shaped, somewhat resembHng that 

 of H. armata, but eccentric, and situated towards the right lateral border of 

 the ventral surface ; the stem or shaft of this hammer-like structure fastened 

 to the cuticula in a line parallel with the adjoining margin ; its thickened 

 anterior end produced outwards and at right angles as a stout, recurved, 

 pointed hook, a second slender, horny prolongation, which is recurved and 

 continued down and parallel with the left-hand border, being fastened 

 to it, produced from the same thickened distal extremity of the handle-like 

 portion ; the cuticular interspace between the stem of the hook and the 

 adherent recurved prolongation obliquely furrowed from the front and right 

 towards the posterior and left, these furrows further continued as fine longi- 

 tudinal striae over the remaining dorsal and ventral cuticular surfaces ; a row 

 of contractile vesicles developed along both the right and left-hand borders ; 

 endoplast almost as long as the body, cord-like, disposed longitudinally 

 towards the right body-half, its anterior end curved more or less towards 

 the left ; on the right side, a little behind the centre of the endoplast, is 

 attached a small oval endoplastule. Length 1-240". 

 Hab. — Intestinal tract of Liimbriais anatomiacs. 



As many as fifteen examples of this animalcule were found by Stein * in company 

 with several specimens oi Anoplophrya striata, his A. liimbrici, within a single specimen 

 of the above-named annelid ; the occurrence of an exteriorly developed endoplastule 

 or nucleolus has not so far been recorded in connection with any other member 

 of the Opalinidae. 



Hoplitophrya pungens, Stein. 



Body elongate-clavate, somewhat flattened, widest anteriorly ; a trans- 

 versely placed, arcuate, or obtusely-angled horny band, the centre of which 

 is produced forward as a slightly projecting spine, developed immediately 

 behind the centre of the anterior border; endoplast band-like, longitudi- 

 nally placed ; contractile vesicles numerous, arranged lineally along the 

 right and left borders of the body. Dimensions unrecorded. Multiplication 

 as in H. secans. 



Hab. — Intestinal tract of ScBuuris variegata. 



Hoplitophrya secans. Stein. 



Body elongate, band-like, slightly widest and rounded anteriorly, a 

 horny keel-like band, widest in front and tapering posteriorly, developed 

 on the ventral surface from the anterior end backwards to the median line ; 

 contractile vesicles numerous, located close to one another along the centre 

 of the dorsal line ; endoplast cord-like, axial, thicker than in H. securiformis. 

 Dimensions unrecorded. 



Hab. — Intestinal canal of Luinbriculus variegdtus, and Eiichytrceus 

 vermicular is. 



When multiplying by transverse fission this species does not divide into two 

 equal portions, but through the constriction and subsequent separation off of small 



* ' Sitzungsberichte d. konigl. Bohmischen Ges. d. Wiss.,' 1861. 



