Cope.J '^■^'-' [April 1, 



oblongus, sp. nov. Osteolepis or Megalichthys, fragments. Holoptycldus 

 americanus Leidy. Holoiytychius giganteus Agass. 



From Chemung beds near Leroy I obtained : 



Holonema rugosum Clay p. Eolonema liorridum, sp. nov. HoloptycMus 

 filostts, sp. nov. 



From another locality, probably Chemung, near Leroy : 



Bothriolepis minor Newb. Coecosteus maeromus, sp. nov. Osteolepis 

 or Megalichthys, fragments. 



At the last-named locality the specimens are very abundant, but mostly 

 dissociated, so that it is rarely that two pieces of the same fish are found 

 in their natural relations. The bed where they occur is in some places 

 carbonaceous from the abundant organic matter deposited there. Frag- 

 ments of the Osteolepid fish above referred to are abundant, but they are 

 too scattered for identification. 



To the species found in Pennsylvania, I add the description of a fine 

 Megalichthys from the Carbonic of Kansas. 



OSTRACOPHORI. 



Holonema horridum, sp. nov. 



This large species is represented by the nearly perfect mold of a plate 

 whose position may be determined by the following considerations. It 

 has almost exactly the form of the lateral plate of the specimen of the 

 Holonema rugosum Clayp., to which I referred in describing the supposed 

 pectoral spine of that species.* From the fact that the specimen referred 

 to presents two median scuta, I have supposed that it is a part of the car- 

 apace. It is, however, true that the exposed surface of the long anterior 

 median plate is acuminate in front, showing that the anterior lateral 

 plates join anterior to it. This is not known to occur in the carapace, but 

 is characteristic of the plastron. That this conclusion is correct is shown 

 by the character of the median posterior scute of //. rugosu/n, shortly to 

 be described. This being the case, it is necessary to admit that there are 

 two median scuta, a character thus far unknown in the Antiarcha, and 

 one which distinguishes the genus Holonema from Bothriolepis. 



On this interpretation, the scute to be described is the posterior lateral 

 of the left side of the plastron. It is about three fifths the size of that of 

 the Holonema rugosum. and is considerably longer than that of the Bothri- 

 olepis nitidus Leidy. It differs from both species in its superficial sculp- 

 ture. In the last-named species this is generally concentric to a non-cen- 

 tral point. In the HolonenKt r^tgosum the sculpture radiates from a more 

 or less central point. In the present species the pattern is longitudinal 



* Proceedings U. S. Natl. Museum, 1891, p. 45G. 



