A New Species of Lancelet, Branchiostoma longirostrum (Order Amphioxi), from the Western North Atlantic

Branchiostoma longirostrum n.sp. (order Amphioxi) is described from specimens in the northern and eastern Gulf of Mexico, and the east coast of Florida. The new species is distinct in having the combination of few dorsal fin-ray chambers (x̄ = 237), high total myotome count (x̄ = 61.3), and a relatively large rostrum (percent of TL, x̄ = 2.91). It is compared with B. virginiae and B. bennetti, its probable nearest relatives, as well as with B. floridae and B. bermudae