CIILAMYDOSELACIIUS ANGUINEUS. 41 



From the data at hand it is not possible to detornune the variation 

 in the specimens taicon at tliese widely distant localities. It is true 

 that Gunther found but twenty-five teeth on the lower jaw of his 

 ppecimen, and that Kners specimen had but twenty-six, but it must 

 be remembered that these specimens were ten inches or less in leno-th 

 while the individual taken by the " Albatross," having thirty-one teeth on 

 the lower jaw, has a length of more than eighteen inches, which at once 

 raises questions as to differences in this respect on account of age. 



CHLAIMYDOSELACHID.-E. 

 Chlamydoselachus anguineus. 



Chlamydoselachus -xngiiineus Garman, 1884, Jan. 17, Bull. Essex Institute, Vol. XVI., with figures ; 

 1884, Feb. 1, Science, p. 116; 1884, March 21, Science, p. 345; 1884, Xov. 28, Science, 

 p. 484; 1885, July, Bull. Mus. Comp. Zoo]., Vol. XII., No. 1, with 20 plates; 1885, 

 July, Proc. Amer. Assoc. Adv. Sci., 537; 1887, March 18, Science, p. 267. 



Didymodus anguineus Cope, 1884, March 7, Science, p. 275; 1884, April, American Naturalist, 

 p. 412; 1884, May 30, Science, p. 645; 1884, "Printed July 1," Proc. Amer. PhiL Soc, 

 p. 572. 



Plate LXX., Lateral Canal System 



This shark is one that may confidently be expected to appear iii future 

 collections from the region about the Galapagos. It occurs in both the 

 Atlantic and tlie Pacific, like Isistius and Centroscyllium ; it is of present in- 

 terest mainly in comparisons. At different times the Museum of Comparative 

 Zoology has come into possession of several specimens and opportunity has 

 been taken to verify items originally derived from the type. As long ago 

 as 1886, on the arrival of a second individual from deep water near Tokj-o, 

 Japan, it was seen that the tail of the type was deformed, as previously 

 suspected, and the following note was printed by the writer in '•' Science," 

 Vol. IX., No. 215, p. 267, March 18, 1887. '^ The Tail of CJdanujdosdachus. 

 A recent opportunity of examining a second specimen of Chlamydoselachus 

 furnished the means of adding an item or two to our knowledge of that 

 peculiar genus. In several points the example differed from that originally 

 described. This was notably the case with the tail. On the later capture 

 this organ was a little more than one-fourth of the total length, and, with 

 the vertebral column, tapered to a sharp extremity; whereas in the first one 

 it stopped abruptly, with vertebrae of considerable size, as if truncate. On 

 the new one, the lateral line, with a few short breaks posteriorly, continued 



