[69] NOTES ON ENTOZOA OF MARINE FISHES. 787 



ular organ, which was sharply differentiated from the surrounding parts 

 and measured ,2 mm in length and .24 mm in breadth. The outlines of the 

 uterus could not be made out from the sections but amber-colored eggs 

 were found in clusters elongated transversely, in marginal prolonga- 

 tions of a median cleft of the proglottis. 



In one of the mature segments ova were found that had begun to 

 undergo segmentation. In one case four distinct cells were observed in 

 a single ovum. 



Phyllobothrium Yan Beneden. 



Body articulate treniseform, head separated from the body by a neck, 

 with four opposite sessile bothria, each bothrium lacinio-crispate on the 

 margin and provided with a single ampulla-like supplemental disk. 

 Genital apertures marginal. 



The species which I refer to this genus resembles Yan Beneden's P. 

 auricula, but differs from it in having the bothria pediceled in marginal 

 pairs, a feature, which, it would seem, requires the generic characters 

 to be emended so as to admit this peculiarity. 



I have referred Phyllobothrium thysanocephalum, of my former paper 

 to the new genus Thysanocephalum, of the sub family Phyllacanthinw, 



, 15. Phyllobothrium foliatum sp. nov. 

 [Plate vi, Figs. 5-10.] 



Head broad and flat. Bothria four thin, leaf-like, sessile iu marginal 

 pairs, each pair mounted on a short, stout pedicel. Faces of bothria 

 finely reticulated, directed forward ; borders of bothria with a distinct 

 row of loculi, and with crenulate margins. Edges of bothria more or 

 less ruffled and folded. Each bothrium provided with a single supple- 

 mental disc on its anterior edge. Neck long, broad, and flat, immedi- 

 ately behind the head, quickly narrowing and becoming cylindrical, 

 merging into the body. Segments begin as fine, transverse lines on the 

 neck, first distinct segments very short, appearing as transverse, 

 crowded wrinkles. Subsequent segments increase in length, becoming 

 as long, as broad, and ultimately longer than broad. Mature segments 

 with convex margins, appressed at the two extremities, but most at the 

 anterior end, many of them, therefore, flask-shaped. 



In alcoholic specimens, median part of body thickened and fusiform, 

 posterior segments often elliptical, and posterior part of strobile, there- 

 fore moniliform, neck sometimes extremely attenuated. 



Genital apertures marginal, near middle of margin. Cirrus echinate. 

 Length, maximum, 185 mm . 



Habitat — Trygon centrura, spiral valve, August 1, 1887, very numer- 

 ous. August 8, one specimen. August 10, four specimens. Wood's 

 Holl, Massachusetts. 



The following measurements are of a living specimen of the first lot : 

 Length, 85 mm ; breadth of head, 3 mm j thickness of liead ? ¥* m : greatest 



