Sir P. Egerton on the Fishes of the Old Red Sandstone. 445 



May 18, 1859. — Major-Gen. Portlock, Vice-President, in the Chair, 

 The following communications were read : — 



1. " Palichthyologic Notes, No. 12. Remarks on the Nomencla- 

 ture of the Fishes of the Old Red Sandstone." By Sir P. Egerton, 

 Bart., M.P., F.R.S., F.G.S. &c. 



Premising with some remarks on the in many respects unsatis- 

 factory condition of the nomenclature of the fishes of the Old Red 

 Sandstone, the author refers to the late revival, by Dr. Pander, of 

 the discussion as to the priority of Eichwald's name " Asterolepis " 

 over the " Pterichthys" of Agassiz; and, after a detail of the circum- 

 stances of tlie case. Sir Philip states that there is every reason for 

 the retention of the name Pterichthys for the " winged fish " dis- 

 covered at Cromartie by Miller in 1831, introduced by him to the 

 scientific world in 1839, and named Pterichthys by Agassiz in 

 1840. 



The author then proceeded to offer some critical remarks on several 

 of the genera and species which Prof. M'Coy has described from the 

 Old Red Sandstone. Chirolepis velox, M'Coy, is regarded by him as 

 a good species ; but C. curtus as identical with C. Cummingice, and 

 C macrocephalus with C. Traillii. Chiracanthus grandispi7ius and C. 

 pulverulentus are regarded as good species ; but C. lateralis is referred 

 to C. minor. Diplacanthus gibbus and D. perarmatus are accepted. 

 The substitution of Bii^lopterax for Diplopterits is not considered ne- 

 cessary. Diplopterus gracilis appears to be a variety of D. Agussizii. 

 The occurrence of D. macrolepidotus in Caithness, and the restriction 

 of D. macrocephalus to Lethen-bar and Russia, are regarded as a 

 reason for not accepting Prof. M'Coy's view as to the identity of 

 these two forms. 



Osteolepis arenatus, stated by Prof. M'Coy to occur at Orkney, has 

 been met with only in the Gamrie by Sir Philip. 0. brevis is regarded 

 as a good species, though the apparent breadth of the head has pro- 

 bably been misunderstood. Hugh Miller has well figured and de- 

 scribed the cranial anatomy of this species in the ' Footprints.' 

 Triplopterus Pollexfeni is also considered to be well established ge- 

 nerically and specifically. Sir Philip coincides with Prof. M'Coy in 

 classing Dipterus with the Cmlacanthi, but observes that it is distinct 

 from Glyptolepis. Bipterus has but one anal fin. Bipterus hruchy- 

 pygopterus and B. macropygopterus are, in the author's opinion, 

 synonyms ; but B. Valencienncsi is regarded by him as distinct. 



Cmichodus is esteemed by the author only a provisional genus. 



Sir Philip agrees with M'Coy in separating from the Holoptychius 

 the large fishes of the Coal-measures which have received the name 

 Rhizodus from Prof. Owen. The latter have an ossified vertebral 

 column. Holoptychius has decidedly two dorsal fins. Some good 

 specimens lately obtained at Dura Den prove that //. ylndcn^-o/ii 

 and //. Flcmingii are specifically the same. 'I'he determination of 

 H. princeps by scales alone is not regarded as satisfactory ; but //. 

 Sedgwickii is a good species. Gyroptychlus ungustus and G. diplo- 

 pter aides are considered as good species of a new and important genus ; 



