[113] NOTES ON ENTOZOA OF MARINE FISHES. 831 



The bothria are very mobile in life, being sometimes turned forward 

 so as to present two capping dishes directly in front; at other times 

 both are turned over so as to be applied to the same surface, when they 

 act as suctorial discs to aid the worm in locomotion. The edges of the 

 bothria are somewhat thickened, the face hollowed out and the poste- 

 rior margins emargiuate. This latter feature is retained in but few of 

 the alcoholic specimens, and in them usually with not much distinct- 

 ness. 



On two different occasions I have observed what I am disposed to 

 interpret as embryos which have escaped from the ova before leaving 

 the mature segments. They presented exactly the same character on 

 each occasion. They are long ovate, or rather conical, broadly rounded 

 at one end, tapering to a point at the other, with a few clusters of curved 

 bristle like spines at the smaller end, and near the larger end. They 

 were first noticed in the summer of 1886, when they were seen, along 

 with undoubted ova, issuing from living segments in sea-water. They 

 measured .055"" u in length and .023 mm in diameter near larger end, while 

 the length ot the bristles was about .012 mm . The ova were about the 

 same length as these bristle-bearingembryosandtwiceas broad. In July, 

 1887, while examining some specimens of this rhyuchobothrium which 

 had been placed in sea water under a compressor, I observed multitudes 

 of these highly characteristic objects. They were .04S mm in length and 

 .01G' nm in breadth at larger end. It was observed that segments of this 

 worm, after lying for a few minutes in sea water, burst at irregular 

 places, allowing the escape of these embryos. Along with these conical 

 bodies were great numbers of small globular masses ,0076 mra in diam- 

 eter. The latter were highly refractile and contained two or three, 

 sometimes more, nuclear granules. They probably come from a layer 

 of roundish granular bodies which lie beneath the muscular walls of the 

 segment. In a few instances the wall of a segment was observed to 

 swell out into one or more bud like prominences from which the em- 

 bryos and the small refractile bodies presently burst forth. The em- 

 bryos, after having been discharged for about an hour in sea water, 

 changed from a transparent or translucent white to a very dark brown 

 or black. My attention was first called to this fact by noticing patches 

 of some black substance in the bottom of a dish of sea water in which a 

 number of these worms had been placed. Upon examination these 

 patches proved to be made up of these characteristic embryos, but 

 most of them quite black. A few were unchanged, or but little changed. 

 In the dark-colored ones the bristle-like spines are much more dis- 

 tinct than in the colorless ones. This is doubtless due to the change 

 of color which affects the bristles as well as the rest of the object, 

 making them opaque. These spines are now seen to be strongly 

 curved, to occur at the smaller end and also in a ring of irregular 

 bunches near the larger end. No movements were observed in any of 



