272 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.52. 



preserved in the Peabody Museum; a single specimen is found in the 

 Museum of Comparative Zoology at Harvard College, and two others, 

 both in counterpart and very well preserved, are the property of the 

 United States National Museum. They were formerly in the Lacoe 

 collection, and one of them bears an original label in Newberry's 

 handwriting which reads: " Palaeoniscus gracilis "New.'^ It is cata- 

 logued as No. 4398, and is the origmal of our plate 10, figure 1. 

 Whereas m the type-specimen only about nme caudal fin-rays are to 

 be counted above and below, this specimen shows at least thirteen 

 in the lower lobe. 



Formation and locality. — Coal Measures; Mazon Creek, Illinois. 



Genus PALAEOPHICHTHYS Eastman. 



This peculiar crossoptcrygian genus has been provisionally referred 

 to the Coelacanthidge, but is distinguished from all other members of 

 the family by its elongate, anguilliform body and continuous median 

 fins. In the latter respect an agreement is to be noted with the 

 specialized and problematical genus Tarrasius, from the Lower Car- 

 boniferous of Scotland, and also with Concliopoma gadiforme Kjier, 

 from the Lower Permian of Rhenish Prussia. Possibly both Tarra- 

 sius and Conchopoma should be regarded as aberrant Coelacanths. 



PALAEOPmCHTHYS PARVULUS Eastman. 



riate 10, fig. 2. 



Palaeophichthys parvulus Eastman, Ann. Rept. Iowa Geol. Surv., vol. 18, 1908, 

 p. 253, fig. 37. 



This is a very small species, attaining a total length of about 5 cm., 

 with a remarkably short head and slender, elongated, anguilliform 

 body. The median fins are continuous, the dorsal arising behind the 

 occiput at a distance equal to about one-and-one-half times the 

 length of the head itself, and the origin of the anal not far behind the 

 middle of the body. 



Besides the holotype of this interesting small species, but a single 

 example has come under the writer's observation. It is a specimen 

 formerly in the Lacoe collection, now the property of the United 

 States National Museum, and catalogued as No. 4453. The nodule 

 in which it is contained would seem to have been fractured by natural 

 means and to have been exposed to atmospheric agencies for a 

 considerable time, thus permitting oxidation to take place over the 

 surface with consequent obliteration of a good many structural 

 details. Thus, the precise pomt of origin of the median fins is indeter- 

 minable, the head bones are confused, and although the neural and 

 haemal arches are clearly indicated m the anterior half of the trunk, 

 they cease to be visible in the caudal region. Under the lens it is 



