26 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 64. 



So far as I am acquainted with the literature of this species, ripe, 

 or even adult, proglottides have not been found attached to the stro- 

 bile of THlocularia. Luehe's species, Urogonopoms armatus:^'^ was 

 rightly regarded, I think, to be a free cestode proglottis.^^ As to 

 its being the free proglottis of T. gracilis^ as Olsson argues, that is 

 a point which does not seem to me to be satisfactorily established. 

 The presence of spines on TJ . armatus is hard to account for, if it 

 is from the strobile of T. gracilis^ the strobiles of which are not rep- 

 resented as being armed. In cestodes which are characterized by 

 the possession of cuticular spines, the spines are most strongly de- 

 veloped on the anterior portions of the strobile, and are usually 

 absent, or lingering but sparingly, on the mature proglottides. 



None of the strobiles in my collection have the slender proglottides, 

 shown in Olsson's figure 27, but the resemblance to his figure 26 ^^ is 

 striking. 



On one of my slides there are two ripe segments mounted along 

 with scoleces of T. gracilis. One of these measures 2.8 mm. in 

 length and O.T in breadth. It is fusiform and practically filled with 

 ova, except for a small area at each end. The ova do not have sharp 

 outlines, but appear to be from 0.015 to 0.018 mm. in diameter. The 

 genital pore is near the middle, or a little in front of the middle of 

 a lateral margin. These proglottides may or may not be the prog- 

 lottides of T. gracilis. 



This cestode is characterized by having the bothria divided by a 

 transverse septum near the anterior end into two parts, the poster ior^ 

 and larger of which, being divided by a median septum, so that the 

 bothria become triloculate. 



Squalus acanthia^. 



Collected in 7 of the years from 1903 to 1914. On 4 dates in May : 

 (1) Numerous young cestodes, resembling Scolex polymorphus, but 

 with characteristic triloculate bothria; strobiles taper to posterior 

 end, which is frequently curved; length of longest 5 to 6 mm., 

 diameter of scolex 0.9 mm.; (2) 6, maximum 16 mm., 9 dogfish ex- 

 amined; (3) 1 scolex found adhering to a free proglottis of Antho- 

 hothrium pulvinatmn, in a lot of formalin material from the spiral 

 valves of 40 spiny dogfish; breadth of bothrium 0.56 nmi. ; (4) 1, 

 length 10 mm. On 1 date in June, 4, found adhering to specimens 

 of Phyllohothriuni loliginis; length 1.73; length of bothrium 0.31, 

 breadth 0.30; diameter of neck 0.18; bothria in pairs on lateral mar- 

 gin, covered with minute, stout bristles. On 2 dates in September: 

 (1) 10, from spiny dogfish taken by the steamer Fish Hawk on Crab 

 Ledge, off Chatham, Mass., in 16 fathoms, 6 dogfish examined. The 



"Archiv. de Paraslt., vol. 5, 200-2o0. " j^unds Univ. Aipsk., vol. 3. pi. 2. 



" Idem, vol. 8, 465-471. 



