392 GEOLOGY OF NORTHWESTERN TEXAS. 



Vertebrates. — Very few fragments of vertebrates have been collected in 

 the strata, and they have generally been of such a fragmentary character that 

 nothing could be made of them. 



Edestus Minor. — A single specimen of this rare fossil was found in the 

 black shale about one mile west of the town of Bend, in the southeast corner 

 of San Saba County. 



This species has never been found anywhere except in the Coal Measures. 

 Professor Newberry says, after giving the locality of several specimens: 

 "Thus it will be seen that all the specimens known, now quite numerous, are 

 from the Mississippi Coal Field, that is, the coal area of Illinois and Missouri, 

 once continuous but now separated by the erosion of the immediate valley of 

 the Mississippi " * 



It has been stated elsewhere in this Report that the Texas Coal Field is a 

 part of the Mississippi Coal Field, and the conclusion that Dr. Newberry 

 reaches, that it was a fish peculiar to the Western Coal Field, is not contra- 

 dicted by the finding of this specimen in Texas. 



Articulates — Two species of Trilobites have been found belonging to the 

 genus Phillipsia. They are not abundant, and have only been found at a few 

 localities. Some of them are well preserved. 



Mollusks. — This sub-kingdom is well represented by the several classes, 

 Cephalopoda, Gasteropoda, Lamellibranchiata, Brachiopoda, and Bryozoans. The 

 Cephalopods are numerous in genera and species. Some of these are de- 

 scribed for the first time in this Report by Prof. Alpheus Hyatt. 



The Gasteropods are represented by several species in well preserved speci- 

 mens. The families of Bellerophon and Pleurotomaria are most numerous. 



Lamellibranchs are numerous, represented by the families Aviculopecten, 

 Allorisma, Myalina, and others. 



The Brachiopods are abundant everywhere, being represented by Spirifer, 

 Productus, Chonetes, and other families. 



Radiates. — These are numerous, and are represented by Zaphrentis, Cam- 

 pophyllum, Axophyllum, and Syringopora of the corals, and several species of 

 the Echinoids and Crinoids. 



The Protozoans are represented by Fusulina cylindrica in very great abund- 

 ance, and are found from the bottom to the top of the Measures. If there 

 are more than one species — and that fact is to be determined by the sizes — 

 then there are more than two species in the formation in this State, for they 

 vary very much in size in different horizons. 



There are several undescribed species of fossils occurring at different local- 

 ities, the description of which will have to be deferred to another time. 



* Paleozoic Fishes of North America, P., p, 217, 1880, 



