Fishes of the Western North Atlantic i 3 



Usually each of the genital, urinary, and intestinal tracts opens separately to the 

 exterior, but among the syngnathids (jj: xxvii, ftn. i) and lophotids (information 

 from Vladimir Walters) they empty into a common cloacal pouch. In many, a swim 

 bladder is developed as a single outpocketing from the dorsoanterior part of the di- 

 gestive tract, and an open pneumatic duct persists throughout life in some but not in 

 others; in the polypteroids a functional paired lung is developed as a ventral out- 

 pocketing from the pharynx.'" 



The brain, consisting of a large cerebellum, large optic lobes, and a feebly de- 

 veloped cerebral region, is roofed (typically) in its anterior part with simple nonnervous 

 epithelial tissue. The notochord is more or less constricted segmentally except in the 

 aclpenserids, polyodontids, and deep-sea halosaurids. The jugal sensory canal (forward 

 extension of the lateral line) is represented in most by a horizontal line of sensory pits 

 that cross the cheek region {8g: 378). The pericardium Is thick-walled posteriorly; the 

 heart chambers show no indication of subdivision into arterial and venous channels." 



Nomenclature. The choice of a name for this Subclass lies between Actinopterygll 

 and Teleostomi. 



In 1839 Bonaparte proposed the name Teleostomi'* as a sectio to include his Ga- 

 noidei and certain other groups of bony fishes, but excluding the aclpenserids (sturgeons) 

 and some others (jO: 15). Many years later Owen expanded Bonaparte's Teleostomi 

 to Include the bony fishes as a whole, excepting the Dipnoi, which were unknown to 

 Bonaparte {^y. 7). Since 1868 Teleostomi has been used In this sense by numerous 

 authors. 



The Subclass name ActInopterI,'» changed subsequently to Actinopterygia and 

 Actinopterygll, was coined by Cope to Include the aclpenserids, lepisosteolds, amioids, 

 and all higher groups of bony fishes, except the polypteroids {ly : 449). The Subclass 

 was employed In this same sense by Traquair {8^\ 505, 507), Goodrich (45), Jordan 

 (jp: III), Lehman, Bertin, and Bertin and Arambourg (jj: 2070-2500). In 1928 

 it was expanded by Goodrich to Include the polypteroids {2g: 91), and It has been 

 employed with this modification by Stensio,*" Berg (4: 159, 392), Romer (75: 105, 

 579), and Schultz and Stern {^y. 228). 



Superorders. Several students have distributed the Orders of Actinopterygll among 

 three Superorders, namely: Chondrostei (or Chondrosteoldea) for the aclpenserids (stur- 

 geons) and polyodontids (paddlefishes) ; Holostel for the Lepisosteoldea (gars) and 

 Amioldea (bowfin); and Teleostei for the remaining bony fishes. It does not seem pos- 

 sible to draw a line of distinction between these Superorders if the fossil record be 

 taken into account, hence they are not recognized here." 



36. For discussion of the relationship of swim bladder to lungs, see especially Romer {74: 343-35°> figs. 225, 227). 



37. Among the living Dipnoi, the pericardium is thin-walled, and there is an "incipient division of the heart into 

 a venous and an arterial channel" [45: 249 — Goodrich). 



38. From the Greek words teUos (meaning perfected) and stoma (meaning mouth). 



39. Based on the Greek words aitis, meaning a ray, and pteron, wing or fin. The spelling was later changed to 

 Actinopterygia by Cope and to Actinopterygii by subsequent writers. 



40. In a series of papers (1932-1936). 



41. For a discussion of this matter, see especially Berg {4: 160-163, or 392-395). 



