399] PSEU DOPEY LLIDEA FROM FISHES— COOPER 111 



punctations, hence the specific names bipunciata and punctata. In this species 

 the uterus-sacs were described by Rudolphi, Leuckart (1819:41), et al., as ar- 

 ranged in a single row, in a double row, or alternating thruout the strobila. 

 They were likewise found to alternate irregularly from side to side (Fig, 60) 

 (e.g., r, 1, 1, r, r, 1, r, 1, 1, r, r, 1, etc.) or to be more medially situated (1, m, 1, 

 m, m, m, m, 1, m, r, r, m, 1, 1, m, m, etc.) but never in two rows, ex- 

 cepting in a very few immature genital segments (Fig. 57), unless the alternating 

 condition in much contracted strobilas is considered as such. While the sac 

 has a diameter of about 0.18mm. when the first eggs appear in its lumen, it 

 may reach a length of 0.35mm. and a transverse diameter of 0.22mm. or about 

 one-sixth of that of the proglottis. The combined uterus-sac and uterine duct 

 may in many cases occupy more than one-third of the width of the segment. 

 The hindermost segments, in which the uterus-sacs may be gorged with eggs 

 to a diameter of 0.65mm., separate from the chain evidently in pairs, the Unes 

 of division taking place at the furrows between the larger crenulations men- 

 tioned above. No detached proglottides were found free, however, in the intes- 

 tine of the host, altho Olsson (1867:55) recorded having found such, while 

 Weinland (1858:9) said that, according to Eschricht, the species "which Uves 

 in the sculpin of the Baltic (Cottus scorpius) throws off its whole chain of joints 

 every year and then sends out a new one from the neck. " Like that of the 

 distal portion of the uterine duct the wall of the sac is composed of a much 

 attenuated epitheUum from the basement membrane of which the nuclei, 

 separated by wide intervals, project into the lumen like bosses. The uterus- 

 opening is situated ventrally in the middle of the uterus-sac, and with regard 

 to the external segmentation either in the middle of the larger (double) seg- 

 ment or in the groove separating it from the next ahead or behind. Circular 

 in outline and 50/x in diameter, it is surrounded by an area of radiating nuclei, 

 thought by Lonnberg to be possibly of the nature of a gland for the secretion 

 of a material of use in the passage of the eggs to the exterior. The actual 

 opening is formed by the rupture of a membrane guarding the outlet, which 

 has a thickness of from 15 to 30n, (cf. C. crassiceps). 



The fresh egg is elHpsoidal in shape, dark brown in color, and measures from 

 66 to 80/i in length by 43 to 45/x in transverse diameter. The shell was ob- 

 served to be about 9/x thick in living material and not provided with an oper- 

 culum. No mature eggs showing the six hooks of the oncosphere were met 

 with in fresh material in the field. 



Nothing was discovered regarding the intermediate host or hosts of this 

 species, not even in the way of food-contents, for the stomachs and intestines 

 of the few sea-ravens examined were all found to be empty. Linton (1890 :732) 

 gave as the food of Lophopsetta maculata and Limanda ferruginea, from which 

 he recorded Dibothrium puitctatum Rud., "several species of AnneUds, frag- 

 ments of Squilla, and several specimens of a species of Margarita. " No speci- 

 mens smaller than about 25mm. in length were obtained. According to 

 Udinsky's abstract, Pilat (1906:191), working on B. scorpii from Raja clavata 

 of the Black Sea (the only case of the species having been found in a selachian 



