GIRTY, NEW CARBOXIFEROUS FOSSILS 319 



Camarotoechia purduei sp. nov. 



Shell rather large, a leugth of 15 mm. being about the maximum. Length 

 and width nearly equal, the one being greater in some specimens and the 

 other in others. Outline variable, subtriangular, subpentagonal or subovate, 

 the greatest width being sometimes nearer the anterior end and sometimes 

 about midway. Beak of the ventral valve small, suberect and somewhat flat- 

 tened. Fold and sinus strongly elevated and sharply defined. 



Surface marked by subangular plications reaching backward to the beaks. 

 As a rule, 4 of these occupy the fold and 3 the sinus, but in many instances the 

 fold has 3 and the sinus 2 plications. Rarely are 5 developed on the fold. 

 When 3 are present, sometimes they are of equal size, but sometimes the 

 median one is larger and more elevated so that the fold and sinus are pointed. 

 In some cases, 3 of the mesial plications are equally elevated, while the fourth 

 is developed on one side of the fold or on the other. In a few cases, there are 

 3 mesial plications and an additional one on either side, making 5 altogether. 

 As a rule, the 4 plications are of equal size and elevation. The lateral plica- 

 tions number 5 usually, but occasionally 6 and sometimes 4 or even 3. The 

 plications vary in different specimens in size and angularity. Some specimens 

 are more tumid than others, and in some the front is rounded downward, thus 

 obscuring the fold, which is usually highly and abruptly elevated. 



Although from this it will be inferred that specimens might be se- 

 lected to present rather widely different expressions, as a whole these 

 shells make up a fairly uniform group. 



Camarotoechia purduei var. laxa var. nov. 



In a few instances, there have been obtained specimens which seem to 

 deserve recognition as a distinct variety, though their relationship to C. 

 purduei can not be doubted. They have about the same number of plica- 

 tions similarly arranged, their chief claim to distinction resting on the 

 fact that while in the typical variety the plications are rather angular, 

 in the present one they are obsolescent, depressed-convex and separated 

 by narrow, shallow striae. The plications in this condition appear to be 

 somewhat coarser, but apparently they are not so, as the number remains 

 about the same. 



Harttina brevilobata var. marginalis var. nov. 



The shells referred to H. hrevilobafa are only two in number. Our 

 collection contains, however, a series of specimens rather numerouo, 

 which are of the same general typo as the others, liut differ in being, 

 though larger, much less convex and marked by less deep fold and sinus 

 and less distinct lobation. Even the examples in which these characters 

 are most marked are evidently inferior in their development to the speci- 



