[61] NOTES ON ENTOZOA OF MARINE FISHES. 779 



less compact mass of crisp folds, sometimes expanded into long, curved 

 aiiriculate or leaf-like flaps. Borders of bothria with a row of small 

 locali which give a crenulate outliue to margins and a costate appear- 

 ance to the auriculate flaps. Behind the bothria the head is quadrato- 

 pyramidal tapering posteriorly, prolonged anteriorly into the pedicels 

 of the bothria. Neck short. First segments short and. crowded, me- 

 dium and posterior segment squarish or elongated, according to state 

 of contraction. Free proglottides four to eight times as long as broad, 

 with irregular outlines. 



Genital apertures, male and female approximate, in a marginal de- 

 pression about the posterior third. Maximum length 90 ,um . 



Habitat, — Trygon centrura, spiral valve, August, 1884, July 29, 1886; 

 four specimens on each occasion. Wood's Holl, Massachusetts. 



I append the following additional data obtained from a lot of speci- 

 mens collected July 29, 188G. 



The specimens in this lot measured, while living, 66, 74, 82, and 90 mm 

 respectively. The bothria of all were finely frilled on the edges. The head 

 of one of the specimen measured 2 mm in breadth and 1.15 mm in thick- 

 ness. The free proglottides, which accompanied these specimens, were 

 quite active and exceedingly changeable in form. Their usual shape 

 was elongated with the anterior end contracted into a kind of knob. 

 The greater number of these proglottides while they were yet in the 

 water and active burst open on one of the lateral faces. From the lat- 

 aral apertures thus formed, ova and a part of the genitalia were forced 

 out. The latter remained protruding from the lateral aperture as an 

 ivory-white, cotton-like mass. The cirrus, which was protruded in 

 many cases, is very long and slender. 



The living ova were comparatively large. Each one consisted of a 

 transparent globular pellicle, within which were from three to five gran- 

 ular masses, which seemed to be nuclei undergoing normal develop- 

 ment. The diameter of a single ovum was ,18 mm . The diameter of a 

 single granular mass .02 mm . 



A re-examination of the mature segments with the aid of thin sec- 

 tions enables me to add the following data regarding the anatomy. The 

 convoluted mass of tubes in the center of the posterior segments ap- 

 pears densely striated in a section stained with carmine. It is evi- 

 dently the vas deferens crowded with spermatozoa. In the anterior 

 part of the section there are numerous circular patches of granu- 

 lar and striated tissue. The large, globular granular masses which 

 fill the anterior two-thirds of the median segments are evidently the 

 spermatic capsules of the testes. The cirrus is long and densely cov- 

 ered with spines, which appear to be easily removed from the protruded 

 organ. The spines at the base of the cirrus are relatively long, rather 

 slender, nearly straight, slightly recurved at the slender point and have 

 a short basal articulation. Length of spine at base of cirrus, in one case 



