SYSTEMATIC CATALOGUE OF FISHES. 27 



Class LEPTOCARDII. The Leptocardians. 



Order AMPHIOXI. The Cirristomes. 



Family BRANCHIOSTOMID^. The Lancelets. 



Very small, elongated, compressed, translucent marine creatures, having no 

 scales, rudimentary fins and eyes, the mouth a longitudinal slit surrounded by a 

 fringe of cirri, and various other characters shown in the foregoing key. There 

 are two or three genera and about eight species, distinguishable chiefly by the 

 number of muscular bands with which the body is marked; only one genus is 

 represented in United States waters. 



Genus BRANCHIOSTOMA Costa. Lancelets. 



Small, lance-shaped animals living buried in sand in comparatively shallow 

 water, with gonads on both sides of the median line, an anal fin containing traces 

 of rays, and no caudal fin. Represented on the United States coasts by two or 

 three species, of which one is found in North Carolina. {Branchiostoma, gill- 

 like mouth, the cirri having been mistaken for gills.) 



1. BRANCHIOSTOMA OARIB^UM Sundevall. 

 Lancelet; Amphioxus. 



Branchiostoma caribxum Suadsvall, Kongliga Vetenskaps-Forhandlingar, 12, 1853; St. Thomas and Rio Janeiro. 

 Yarrow, 1877, 218; Beaufort. Jordan & Evermann, 1896, 3, pi. i, fig.l; Beaufort, N". C., to South America. 

 Amphiorus, Baird, S.-nithsonian Report, 1860, 71; Beaufort. Wilson, 1900, 354; Beaufort. 

 Amphioxus caribceus, Jordan & Gilbert, 1879, 388; Beaufort. 

 Branchiostoma larweolatum, Jordan, 1886, 26; Beaufort. Jenkins, 1887, 83; Beaufort. 



Diagnosis. — Depth about .11 total length; number of muscular bands (myocommata) 

 about 58, of which 7 to 10 are posterior to vent; gonads on each side 22 to 26; length under 2 

 inches. (Named from the Caribbean Sea.) 



Fig. 2. Lancelet. Branchiostoma caribaum. 



This curious and interesting species, which is probably only a variety of 

 Branchiostoma lanceolatum of Europe and Chesapeake Bay, is found coastwise 

 from North Carolina to Argentina. The presence of the amphioxus in United 

 States waters was first determined by Dr. Theodore Gill, from specimens collected 

 at Beaufort in 1860. Yarrow found a number of specimens on Bird Shoal, and 

 others have obtained the species there. Wilson states that it is not common at 

 Beaufort and that the pelagic larvae are taken there in the tow in July. In 1902 

 the Fish-Hawk dredged many specimens at various points off Cape Lookout 

 (stations 7312, 7320, 7338,7341) in depths of 8, 10, 13.5 and 29 fathoms. 



