604 GLEANINGS AMONG THE PLEURONECTIDS. 



dd. Pectoral fin of blind Bide wanting; eyes very close together; caudal Jin sub- 



sessile; teeth small, uniserial ; mouth mod- 

 erate ; lateral line of eyed side arched, that of 

 right side less so or nearly straight ; dorsal fin 

 beginning on snout, its anterior rays not ex- 

 sorted, its rays all simple and very numerous; 

 scales small ; body thin, very elongate ; ver- 

 tebra? (sessili-cauda) 43 ; (deep-sea flounders). 



MONOLENE. 



SYNAPTTJRA, NOT BRACHIRTJS. 



I embrace this opportunity also to forestall the retention of the name 

 Brachirm instead of Sifnaptura. Messrs. Jordan and Goss have adopted 

 the former and given their reasons for so doing in the following words:* 



We retain the name Brachirm (i*. e., Brady/chinis), notwithstanding the priority of 

 the name Brachyrus, which seems to have the same meaning. If, however, this 

 name of Swainson be rejected, that next in order of date is Sifnaptura, which has 

 now the advantage of general usage. 



But fortunately we are relieved from adopting that malformed name 

 for the reason that Swainson had, on a previous page of the same work 

 (v. 2, p. 71), applied exactly that form to the genus on a subsequent 

 page (p. 264) designated Brachyrus. On the former page Swainson, 

 comparing the subgenera of Macrochirus (p. 71) or Pterois (p. 2G4), re- 

 marks that "in Brachirm the pectorals are again shortened, and the 

 rays connected and branched." Thus the name is first attached to the 

 group so characterized, and can not be applied afterwards to another 

 genus. Synaptura must therefore be retained, which is fortunate, as it 

 truly "has now the advantage of general usage." 



COINCIDENCE OF INCREASE OF VERTEBRiE AND INCREASE OF LATI- 

 TUDE. 



Messrs. Jordan and Goss direct attention to a certain coincidence be- 

 tween conditions of temperature and dextrality or sinistrality of the 

 species in the following terms: 



As the tropical Hippoglossince and all th9 Pleuronectina>, are sinistral species, th€ 

 eyes and color being on the left side of the body, it follows that the tropical floun- 

 ders are nearly all left-sided species, while those of arctic and antarctic waters art 

 chiefly dextral species, the eyes and color on the right. 



They then advert to the number of vertebra? in relation to conditions 

 of temperature. They say: 



Still more curious is the relation between the number of vertebra* and the geograph- 

 ical distribution of the various species. 



It has already been noticed by Dr. Giinther and others that in some groups o: 

 fishes northern representatives have the number of vertebra; increased. In no groui 

 is this mure striking than in the flounders, as the following table, showing the num- 

 bers of the vertebra; in various species, will clearly show. 



Jordan and Goss, op. cit. , p. 320. 



