NATURAL SCIENCES OF PHILADELPHIA. 



219 



Hippoglossus pinguis Reinh. 

 Reinhardtius hippoglossoides Gill, Cat. 50, 1860. 

 Platysoniatichthys pinguis Bllr., 1862. 

 Hippoglossus groenlandieus Gthr., Cat. iv. 404. 



This species had by common consent been identified with the Pleuronectes 

 cynoglossus of the Fauna Groenlandica afterwards named by Walbaum P. 

 hippoglossoides and by Fabricius P. pinguis until the year 1862. In that year, 

 Dr. Giinther* contended that the ' ' Pleuronectes cynoglossus, Fabr. Faun. Groenl. 

 p. 163, or PL pinguis, Fabr. Vidensk, Selsks. Naturv. Math. Afhandl. i. 

 p. 43, tab. 2, f. 1, is probably identical with PL cynoglossus Gronov. and Linn., 

 as the only difference of any importance appears to be that the Greenland fish 

 is said to have 72 74 rays in the anal fin. It is evident, however, from a 

 single glance at the figure, that it is generically different from Hippoglossvcs," 



The following characters are the most distinctive respectively assigned to 

 the Pleuronectes cynoglossus by Fabricius, and the species of the same name 

 by Giinther. It is necessary, however, to first premise that the true Hippo- 

 glossus vulgaris, as acknowledged by Reinhardt, &c, is first described, after 

 which follows the description of "P. cynoglossus," Fab., which is said to be 

 allied to the P. Hippoglossus, but to be smaller and more oblong. 



Pleuronectes cynoglossus Fab. 



"D. 96. P.M. V. 6. A. 72. 

 "Vix 26 unc. longitudinem et 8 

 unc. latitudinem superanus." 

 Height : Length = 1 : 3. 

 ; Utraque maxilla dentata, dentibus 



curvis, acutis] rarioribus tamen ac in 

 hippoglosso, &c. 



" | Hoc nota differre prcesertim vide- 

 tur a cynoglosso Gronovii in systemate 

 Linneano citato, cui tribuuntur dentes 

 obtusi et cauda subrotunda, quod non 

 ita se habet in pisce grcenlandico : hae- 

 sito igitur, an idem, quod musei gro- 

 noviani possessor determinare valet." 



" Cauda subintegra. \ 



Pl. cynoglossus L., Gthr. 



"D. 102117. A. 

 (10) 1112. V. 7. 



90102." P. 



Height : Length = 1 



3-2| . 



" Upper Jaw with a series of about 

 twenty closely-set, truncated, incisor- 

 like teeth on the blind side.' 1 '' 



Caudal unusually convex or round- 

 ed behind. 



" Lateral line straight, without 

 curve " or noticeable obliquity. 



" Linea lateralis corpori concolor a 

 cervice ad caudam oblique progredi- 

 tur." 



"Cetera ut in prsecedente {Hippo- 

 glossus). 



As negative evidence, the absence, so far as known, of the true Pleuronectes 

 or Glyptocephalus cynoglossus in the Greenland seas, whose Ichthyology is so 

 well known, is one of the strongest, especially as Fabricius states that his 

 species is comparatively abundant and readily caught. 



Equally explicit also is the description of the same species by Fabricius un- 

 der the new name of Pleuronectes pinguis, in the Transactions of the Royal 

 Danish Academy. J 



That description is indeed the amplification of the one in the "Fauna 

 Groenlandica." The fins are described, the caudal as emarginated, the rays 



* litlir. Cat. iv. 450, under Pleuronectes cynoglossus. 



t In P. hippoglossus, "cauda fere integra," in P. platessoides (Hippoglossoides platessoides) "mag- 

 na, lata, varum, rotundata." 



| Det koDgelige Danske Viderskabernes Selskabs. Nat. og Math. Afb. i. (1824,) p. 43, tab. 2. f.l. 



i Sporfinnen er bred, 6malest ved Koden og bredest i ydeiste Rand, hvor den ligesom, rundes 

 ind ad. 



1864.] 



