122 THE CAMBRIAN AND ORDOVICIAN DEPOSITS OF MARYLAND 



specimens cannot be broken out of the rock in recognizable condition. 

 Their cross-sections indicate a general type of structure quite unlike and 

 more advanced than the gastropods found in the underlying Beekman- 

 town limestone. Two fossils, however, both easily recognized, may be 

 found at almost any outcrop of this limestone. One is a coral formed of 

 single tubes, quadrangular in cross-section, but commonly appearing more 

 like calcite stringers in the rock than organic remains. This is the 

 Tetradium syringoporoides described on a later page. The second fossil 

 is a bean-shaped bivalved crustacean allied to Leperditia faculties which 

 occurs throughout the limestone. Other recognizable fossils occur, but as 

 they are more limited in their stratigraphic distribution, details regarding 

 them are reserved for the special discussions of the several divisions. 



Lower Stones River. Although present in several bands of outcrop 

 across Maryland, this portion of the Stones Eiver is usually covered and 

 the character of the rocks can be made out only from a few scattered out- 

 crops. The best development is in the band of outcrop exposed just west 

 of Pinesburg Station and running north almost to the state line. This 

 same band of outcrop is exposed at Martinsburg, West Virginia. Here 

 many of the layers, especially in the upper two-thirds of the member, show 

 sections of undetermined gastropods and pelecypods and of the large 

 ostracod Leperditia fabulites. In the quarries on the west side of the 

 town which expose the lower 200 feet of the formation Ulrich reported 

 certain weathered layers about 125 feet above the base of the formation, 

 from which he collected the following fauna : 



Fauna of Lower Stones Eiver Limestone, Martinsburg, West Virginia 



Girvanella sp. 



Solenopora compacta var. 



Small, undetermined monticuliporoid bryozoan 



Cyrtodonta n. sp. 



Matheria n. sp. 



Liospira cf. obtusa 



Lophospira cf. perangulata 



Lophospira n. sp. of the L. trochonemoides section 



Helicotoma f n. .sp. 



Orthoceras sp. undet. Small, with narrow septa 



Oncoceras ? sp. undet. 



Leperditia fabulites Conrad var. 



