British Protozoa and Zoophytes. 121 



capable of being produced to a remarkable distance as a glassy 

 ribbon surmounted by numerous twining tentacles. The sac 

 usually shows no trace of a nucleus or contractile vesicle, nor 

 are its contents differentiated into an external and internal 

 tissue (ectosarc and endosarc), as in Actinophrys and others of the 

 class ("Acinetiens") into which it has been introduced. The 

 structure of the proboscis differs from that of the sac in the 

 development within it of a clear and highly refractive tissue, 

 corresponding to the muscular element in the branches of Zoo- 

 thamnium and in the more directly contractile pedicle of Zooteirea. 

 In the proboscis of Ophryodendron, as in the body of Epistylis, 

 the contraction of the muscle throws its outer covering into close 

 folds. The tentacles are formed of a continuation of the con- 

 tractile tissue of the proboscis, and are covered to within a short 

 distance of their tips by the integument. The proboscis, when 

 extended, hangs suspended or floating in an erect position, or 

 slowly swims about in large curves by the continuous and very 

 active motion of its tentacles. This animal may be called the 

 homomorph, amongst the Protozoa, of Sipunculus Bernhardt. I 

 have never been able to satisfy myself as to its mode of feeding, 

 though portions of matters are occasionally seen entangled 

 amongst the tentacles, and apparently pressed in contact with 

 the substance of the proboscis. 



In the sketch of this animal appended to my notice of 1859, 

 I figured several globular bodies within the sac, which my friend 

 M. Claparede, to whom I showed it, had not observed; and on 

 further observation I was led to consider the figure erroneous. 

 In March last, however, the Ophryodendra (PI. IV. fig. 1) again 

 contained these bodies ; and by a somewhat " meddlesome mid- 

 wifery," I was enabled to force them from the sacs, and to find 

 that they were living young, from four to nine in number. 



The young thus obtained consist of ovoid bodies of higher 

 refractive structure than the body of the parent, and contain 

 olive-brown corpuscles, shaped like the chlorophyll-granules of 

 Hydra viridis. At a later stage, when the wrinkled trunk of the 

 parent hung lax and dead, the young larvse assumed a pyriform 

 shape, flattened on their inferior surface (PI. IV. fig. 2). This 

 surface was also marked with longitudinal stripe, carrying short, 

 soft, slowly-moving cilia or processes. Their natural mode of 

 extrusion was not observed ; but several families of them were 

 found, each enveloped in a soft gelatinous ball, and attached to 

 the Sertularia and other bodies. Single individuals were seen 

 slowly moving on the zoophyte; and others attached were putting 

 forth the rudiments of the proboscis. The proboscis was at first 

 finely molecular, like the contents of the sac, unwrinkled, and 

 non-contractile. A few tentacles were presently put forth from 



