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 

 acipenserids, 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 Actinopterygii 

 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 acipenserids (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 {^^^ : 7). Since 1868 Teleostomi has been used in this sense by numerous 

 authors. 



The Subclass name Actinopteri,^* changed subsequently to Actinopterygia and 

 Actinopterygii, was coined by Cope to include the acipenserids, lepisosteoids, amioids, 

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

 was employed in this same sense by Traquair (^5: 505, 507), Goodrich (.^5), Jordan 

 (jp: III), Lehman, Bertin, and Berlin 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 {jy. 228). 



Superorders. Several students have distributed the Orders of Actinopterygii among 

 three Superorders, namely: Chondrostei (or Chondrosteoidea) for the acipenserids (stur- 

 geons) and polyodontids (paddlefishes); Holostei for the Lepisosteoidea (gars) and 

 Amioidea (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 {y4: 343-350, 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 ieleos (meaning perfected) and stoma (meaning mouth). 



39. Based on the Greek words aktis, 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 {i^: 160-163, or 392-395). 



