AKT. 16. A>' ATOMY OF DDsOBOTHRIUM LIXTOX. 5 



ning along the median region of one side. The margins are finely 

 crenulated. 



DINOBOTHRIUM PLANUM, new species. 



Figures 2, 3. 7-13. 



r?/pe.— Cat. No. 7602, U.S.N.M. 



On June 24, 1920, a bone shark (CetorJiinus maximus j was cap- 

 tured in the inlet at Menemsha Bight, island of Martha's Vineyard, 

 Massachusetts. Mr. George M. Gray, of the Marine Biological Lab- 

 oratory, Woods Hole, Massachusetts, examined the shark for para- 

 sites and reports that he found but one species of entozoon parasite, 

 a cestode represented by a few specimens in the spiral valve. Three 

 of these worms were given to me by Mr. Gray, with the information 

 that the length of the shark was 25 feet, and that the only identifi- 

 able food which he found was the test of a large species of SaJpu. 

 In the stomach was '• about a half a barrel of red-colored material 

 which looked like tomato ketchup." 



My note made after a preliminary examination of the material is 

 as follows: 



Lengths in alcohol, 145. 440. and 545 mm.: breadth of scolex of 

 largest specimen, 10 mm.: thickness, 5 mm.: length, S mm. This 

 specimen had been preserved in formahn. and was less contracted 

 than the others, which had been fixed in corrosive sublimate. Strob- 

 ile linear with a shallow furrow along the median line of one of 

 the flat sides. There is a tendency to develop fine longitudinal fur- 

 rows, which, with the short segments, impart a somewhat checkered 

 appearance to the surface in many parts of the strobile. Breadth im- 

 mediately behind the scolex, 2 mm. : at posterior end and maximum. 

 4 mm. The proglottides begin immediately behind the scolex where 

 their length is about 0.4 mm. They remain relatively short through- 

 out the length of the strobile. A piece of strobile from the posterior 

 end, and 15 mm. in length, is made up of 21 proglottides, which are 

 filled with eggs. These proglottides are 4 mm. in breadth and 0.7 mm. 

 in length. The proglottides are distinct throughout, with more or 

 less convex outhnes on the margins: genital apertures irregularly 

 alternate and at about the middle or a little anterior to the middle 

 of the length of a proglottis. 



Mr. Gra\- has recently sent me the following additional data: 



He has eight specimens with scoleces and one without. Their 

 lengths in millimeters are: SI. 227, 262. 3S7, 4S7. 6S7. and S25, re- 

 spectively. These were the only internal parasites found. A number 

 of parasitic copepods were obtained. 



The shark is being mounted for the Boston Society of Natural 

 History. 



