﻿1M [ BIRENOIDEI. 



Type. Left palatine dental plate ; Museum, University of Liege. 



A species apparently larger than P. insignis. Palatine dental 

 plates with not less than five widely-spaced, radiating, coronal ridges, 

 coarsely crenulated. 



Form, <y Loc. Upper Devonian : Belgium. 



43605. Plaster cast of type specimen. 



Presented by Prof. P. J. Van Beneden, 1872. 



Palsedaphus lesleyi (Xewberry). 



1875. Heliodus lesleyi, J. S. Newberry, Rep. Geol. Surv. Ohio, vol. ii. 



pt. ii. p. 64, pi. lviii. fig. 18. 

 1889. Heliodus lesleyi, J. S. Xewberry, Palseoz. Fishes X. America 



(Mori. U.S. GeoL Surv. no. xvi.), p. 86, pi. xviii. fig. 3. 



Type. Upper dental plate ; Columbia College, Xew York. 



A species much smaller than either of the preceding, known only 

 by a single example of the upper dental plate ; characterized by 

 eight coarsely crenulated or tuberculated coronal ridges, symmetri- 

 cally radiating, and diminishing in size anteriorly and posteriorly. 



This dental plate is regarded by Xewberry as azygous, repre- 

 senting the ordinary pair of palatine plates, and is thus made the 

 type of a distinct genus, Heliodus. The present writer considers 

 that the specimen is a normal right or left palatine. 



Form. <y Loc. Upper Chemung Group : Xorth Pennsylvania. 



Xot represented in the Collection. 



A portion apparently of a very large dental plate, much resem- 

 bling the palatine of Pcdcedaplius, is described as ArcJueonectes per- 

 tusus, H. von Meyer, Paheontogr. vol. vii. (1859), p. 12, pi. ii. figs. 

 1, 2. The following is the type specimen : — 



33596. Portion of dental plate with parts of four coronal ridges, 

 and showing a large transversely oval foramen near the 

 inner border; Devonian, Gerolstein. The specimen is 

 regarded as the palatal region of a Dipnoan, wanting the 

 dental plates, by A. Fritsch, Fauna der Gaskohle, vol. ii. 

 (1888), p. 90, woodc. fig. 170. Purchased, 1859. 



Also probably closely allied to Paloedaphus is a Dipnoan fish from 

 the Devonian of the Government of Orel, Eussia, of which the frag- 

 mentary mandible was described under the name of Holodus Jcipri- 

 janowi by C. H. Pander, Ctenodipt. devon. Syst. (1858), p. 38, pi. vi. 

 figs. 1-14. In the original description the specimen is regarded as 

 the anterior portion of the skull, and this determination is considered 



