38 bulletin: museum of compakative zoology. 



greatly to be deprecated. Barrande's Coccosteus fritschi, as von Koenen has 

 already surmised, is probably founded on the dorso-median of Aspidichthys. 

 Formation and Locality. — Middle Devonian (fitage Grgi) ; Bohemia. 



Dinichthys tuberculatus Newb. 



1888- Dinichthys tuberculatus, J. S- Newberry, On the Fossil Fishes of the Erie 



Sliale of Ohio (Trans. N. Y. Acad. Sci., Vol. VII. p. 179). 

 1889. Dinichthys tuberculatus, J. S. Newberry, Palaeozoic Fishes of North America 



(Monogr. U. S. Geol. Surv., Vol. XVI. pp. 98, 99, PI. XXXII. Fig. 3). 

 1889. Dinichthys pristulosus {errore), M. Lohest, De la decouverte d'especes ameri- 



caines de poissons fossiles dans le Devonien supe'rieur de Belgique (Bull. 



Soc. Ge'ol. Beige, Vol. XVI. p. Ivii). 

 1892. Dinichthys pustulosus (errore), [E. D. Cope], American Devonian Fishes found 

 in Belgium (Amer. Naturalist, Vol. XXVI. p. 1025). 



It is proper to record this species in connection with the foregoing, not only 

 in order to complete the list of European representatives of the genus, so far as 

 they have been described, but also because this is the only .«pecies of Dinichthya 

 which is known to be common to both continents. This form may be regarded 

 as the connecting link between the Old World species and the New ; not that 

 all the American Dinichthyids were derived from this species, but that this is 

 one of the bonds through which the ancestry of the TVestem fishes can be traced 

 backward to its starting point in Northern Europe. This chain of forms leads us 

 eastward from Manitoba, through Iowa, Wisconsin, and Ohio, to New York and 

 Pennsylvania ; from the last named State D. tuberculatus carries us across the 

 Atlantic to Belgium ; next we meet with D. eifeliensis and D. pelmensis in 

 Germany, followed by one species in Bohemia ; and finally we come up with 

 D. trautscJwldi and D. livonicus associated with the ancestral Coccosteus and 

 other derivatives from the same stock in the Devonian of Northwest Kussia. 



Formation and Locality. — Chemung Group ; Pennsylvania. Psammite de 

 Condroz ; Belgium. 



It remains only to present a description of certain Dinichthyid remains from 

 the Hydraulic Limestone beds of Milwaukee, Wisconsin, a locality from which 

 none have hitherto been known. 



Dinichthys pustulosus sp. no v. 



Plate 3, Fig. 4. 



The F. H. Day Collection, purchased by the Museum of Comparative Zool- 

 ogy in 1881, contains a number of fish rexnains from the Hydraulic Cement 

 Quarries near Milwaukee, Wisconsin. Among them are two plates whose 

 preservation is such as to warrant description, especially since up to the 

 present time but two species (Rhynchodus greenei and Heteracanthus politus) 

 have been noticed from this locality. 



