Cockerell — Some Notes on Fish Scales. 211 



having ctenoid scales on both sides like the soles, namely Ancylopsetta, 

 said to be very close to Paralicldhys.* 



I had readied these conclusions from the scales, when I fortunately mel 

 Professor G. II . Parker, and mentioned them to him. He at once kindly 

 directed my attention to his paper on the optic nerves of flat-fishes, pub- 

 lished in the Bulletin of the Museum of Comparative Zoology, Vol. XL 

 ( L903). In this work he shows that the condition of the optic chiasma 

 in the Soleidse is as in ordinary Teleosts, whereas in the Pleuronectidse it 

 is modified. He therefore concluded that " the Soleidse are not degraded 

 Pleuronectidse, but degenerate descendants of primitive flat-fishes, from 

 which the Pleuronectidse have probably been derived." The Soleid 

 genera examined by Professor Parker were the same as mine; his 

 Pleuronectids were Atheresthes, Eppsetta, Hippoglossoides, Pseltichthys , 

 Paralichthys, Hypsopsetta, Parophrys, Isopsetta, Oncopterus, Limanda, 

 PseudopJeuronectes, Pleuronectes, Liopsetta, Olyptocephalus, Lophopsetta, 

 Platophrys, Syacium, Azevia, Citharichthys , Etropus. Unfortunately, 

 he did not see Ancylopsetta, but it seems very unlikely that it would de- 

 part from the condition he found in all the other genera. 



GADID.E AND ALLIES. 



The table below separates the scales of a number of Gadoids, the speci- 

 mens all from the Bureau of Fisheries Station at Woods Hole, except the 

 Macrouridse, which are (except Macrourus sp. ) from the U. S. National 

 Museum. 



A. Apical field of scales with long spines (Macrouridse). 



Basal circuli sharply angulate in the middle 1. 



Basal circuli not sharply angulate 2. 



1. Apical teeth shorter, densely set, no circuli visible between them 



Macrourus bairdii Goode and Bean. 

 Lat. 39.53 N., Long. 70.9 W. (Albatross). 

 Apical teeth longer, not densely set, circuli very conspicuous be- 

 tween them Macrourus sp. 



Albatross Sta. 2426. 



2. Scale very broad and short; teeth very long, many projecting far 



beyond margin Coryphxnoides rupestris Gunner. 



(Albatross. ) 

 Scale not greatly broader than long; teeth shorter, not or hardly 

 projecting beyond margin . Coelorhynchus caribbeeus (Goode & Bean). 



These scales must be called ctenoid, yet the margin itself is not dentate, 

 except slightly in Macrourus sp. The scales of Capros, as figured by 

 Goodrich, have similar teeth; Capros is, of course, an entirely different 

 fish. 



"Jordan & Evermann, Bull. 47, U. S. N. M., Part III, p. 2634. In this work the scales 

 of Paralichthys oblongus are said to be " weakly ctenoid or cycloid.'' Those examined 

 by me are strictly cycloid. 



