134 NEW YORK STATE MUSEUM 



not indicate immature growth of an individual of either of the other species 

 (i. e. D. terrelli or D. herzeri). The discovery in outcrops of the 

 same horizon, in localities separated by a distance of several miles, of bones 

 of different individuals, all of which seem to agree with one another in their 

 relative proportions, is at least presumptive evidence that these individuals 

 had attained maturity and that the size of the bones given above is that of 

 normal full growth. 



The entire ventral armor of a small Dinichthjid, doubtfully referred to 

 this species, and also a pair of mandibles preserved on a single slab, were 

 obtained some )ears ago by Mr F. K. Mixer from the Black Portage (Rhine- 

 street) shale at Sturgeon Point, on the shore of Lake Erie near Buffalo. 

 The originals, which have been already described by the present writer, are 

 now preserved in the collection of the Buffalo Society of Natural Sciences. 



Formation and locality. Typically from the Styliola layer (Genundewa 



limestone) of the Genesee shale (Senecan) ; vicinity of Bristol Center and 



Canandaigua lake, New York. Possibly also from the Portage beds near 



Buffalo, New York. 



Dinichthys ringuebergi Newberry 



1884 Dinichthys minor R. X. S. Kingufben^ {crrorc). Am. Jour. Sti. [3], 

 27: 476, text fig. I, 2 



1889 Dinichthys ringuebergi /. .V. Newberry. U.S. GeoL Sur. Monogr. 

 16:60 



1897 Dinichthys ringuebergi C. R. Eastman. Mus. Comp. Zool. Bui. 31:40 



An imperfectly definable species, founded upon a detached dorsome- 

 dian plate having a total length of 16 cm, e.xclusive of the well developed 

 carinal process. The external surface is described as having a "finegrained 

 rugose appearance " 1= finely tuberculate ?] and the anterior border is less 

 emarginate than in most species. The type specimen is preserved in the 

 private collection of its first de.scriber, Mr P!. N. S. Ringueberg, of Lock- 

 port, N. Y. A second specimen, presumably of identical nature with the 

 type, and from the same horizon and locality, was obtained by Mr F. K. 

 Mixer a few years ago, and is now preserved in the collection of the Buffalo 

 Society of Natural Sciences. 



Formation and locality. Black Portage ( Rhinestreet) shale ; Sturgeon 

 Point, near Buffalo, N. Y. 



