26 Memoir Sears Foundation for Marine Research 



mens that have been brought up from as deep as 250 to 500 fathoms in closing nets" were 

 taken while in the process of sinking into the oceanic abyss, as may be the eventual fate of 

 all the Amfhioxides that drift out into deep water. 



The frequency with which pelagkus has been reported from deep hauls makes it 

 likely that it can exist for a time in considerably cooler water, although it is primarily 

 tropical in its thermal relationships. But we have yet to learn how low a temperature may 

 be fatal to it, and how rapidly. 



Nothing is known of its feeding habits, nor of those of any Amphioxides. 



Range. Specimens showing the characters of felagicus have been reported from the 

 vicinity of the Hawaiian Islands, the type locality; from numerous localities distributed 

 across the tropical belt of the Indian Ocean between latitudes 10° 8' S. and 9° 6' N. ; from 

 five stations between the St. Helena and Ascension Islands and the African Coast (Lat. 

 about 14° S. to about 4° N.); from one station off the mouth of the Amazon; and from 

 the vicinity of Bermuda, whence 87 specimens were recorded from 27 townet hauls ;"" 

 perhaps also from the Bahamas." 



Synonyms and References: 



Branchiostonui felagicum Gunther, "Challenger" Rep., Zool., 5 (2), 1889: 43, pi. 6, fig. B (descr., ill., N. 

 Pacific near Honolulu); Kirkaldy, Quart. J. micr. Sci., 57, 1895: 320 (mention); Tattersall, Trans. 

 Lpool. Biol. Soc, ly, 1903: 296 (distrib.) ; in Herdman, Rep. Govt. Ceylon Pearl Oyster Fish., Gulf of 

 Manaar, Suppl. 6, 1903: 214, plate not numbered, fig. 16 (descr., Indian Ocean) ; Lonnberg, in Bronn's 

 Klassen, (5, Abt. i, Buch I, 1904: 245 (ref. to type specimen) ; Franz, Jena Z. Naturw., 5<?, 1922: 433 

 (refs., discus., incl. valdiviae) ; Pietschmann, in Kiikenthal and Krumbach, Handb. Zool., <5 (i). Lief I, 

 1929: 109 (discus.). 



Amfhioxides felagicus Gill, Amer. Nat., 29, 1895: 458 (name); Tattersall, Trans. Lpool. Biol. Soc., 17, 

 1903: 275 (diagn.) ; Goldschmidt, Wiss. Ergebn. 'Valdivia,' 12, 1905: 45, pi. I, fig. 3, 4 (descr., ill., 

 Indian Ocean and trop. Atlantic); Willey, Quart. J. micr. Sci., ^o, 1906: 581 (ref. to Goldschmidt, 

 1905); Goldschmidt, Dtsch. Sud-polar Exped. (1901-1903), 11, Zool. j, 1909: 234, pi. 27 (discus., 

 trop. Atlant., chart of distrib.) ; Gibson, Trans. Linn. Soc. Lond., Zool., (2) 13, 1910: 217, pi. 15, fig. I 

 (descr., discus., ill., Indian Ocean) ; Hubbs, Occ. Pap. Mus. Zool. Univ. Mich., 105, 1922: 4 (listed); 

 Goldschmidt, Biol. Bull. Wood's Hole, 64, 1933: 324 (meas., no. of myotomes, discus., Bermuda). 



Asymmetron felagicum Pietschmann, in Kiikenthal and Krumbach, Handb. Zool., 6 (l). Lief I, 1929: 1 10, 

 fig. 107 (ill.). 



Doubtful References: 



Branchiostonui -pelagicum Forster-Cooper, in Gardiner, Fauna Geogr., Maldive Laccadive Archip., i (4), 



1903: 352 (21 mm., Indian Ocean; ident. doubtful because of poor condition). 

 Not Branchiostoma felagicum Parker, 1 904, Bull. Mus. comp. Zool. Harv., 46, 1904: 40, pi. I, fig. I (this 



was valdiviae in reality; see below, p. 28). 



56. Gibson (Trans. Linn. Soc. Lond., Zool., [2] i^, 1910: 214) lists two such instances from the Indian Ocean. 



57. For a list of Bermuda records, see Goldschmidt (Biol. Bull. Wood's Hole, d^, 1933: 322). 



58. A six-mm. specimen from the Bahamas, pictured by Andrews (Stud. Biol. Lab., Johns Hopk. Univ., 5, 1893: 

 pi. 13, fig. 5) as Asymmetron lucayanum, is classed by Gibson (Trans. Linn. Soc. Lond., Zool., [2] 13, 1910: 

 241) as Amphioxides. But Andrews' statement (p. 219) that it had "22 branchial clefts on a side" suggests that it 

 was a specimen in the process of metamorphosis. 



