Acanthopterygil; Synentognathi 43 
ventral fins not used for flight. It is perhaps the most widely 
distributed of all, ranging through almost all warm seas. 
Parexocetus brachypterus, still smaller, and with shorter, grass- 
hopper-like wings, is also very widely distributed. An ex- 
cellent account of the flying-fishes of the world has been given 
by Dr. C. F. Littken (1876), the University of Copenhagen, 
Fia. 339.—Catalina Flying-fish, Cypselurus californicus (Cooper). Santa Barbara. 
which institution has received a remarkably fine series from 
trading-ships returning to that port. Later accounts have 
been given by Jordan and Meek, and by Jordan and Ever- 
mann. 
Very few fossil Exocetide are found. Species of Scombresox 
and Hemirhamphus are found in the Tertiary, the earliest being 
Hemirhamphus edwardst from the Eocene of Monte Bolca. No 
fossil flying-fishes are known, and the genera, Exocetus, Exo- 
nautes, and Cypselurus are doubtless all of very recent origin. 
