388 G. II. Girty — Fauna found in the Devonian 



punctation was observed with the simple microscope employed,* 

 but about the middle of the Devonian punctate shells like L. 

 Williamsana began to appear arid continued through Lower 

 Carboniferous time into the Coal Measures at least. 



The shells in which this character has been observed are 

 given below, but unfortunately it has not been possible to iden- 

 tify with certainty all the forms mentioned. 



Lingula Williamsana n. sp. From the Devonian black 

 shale near Indian Fields, Clark Co., Ky.; near Jefferson vi lie, 

 Montgomery Co., Ky.; and at Berea, Ky.; and also from the 

 Styliola layer of the Genesee at Bristol, Ontario Co., New 

 York, where it is associated with Lingula spatulata, and from 

 Seneca Lake, New York, in the Genesee. 



Lingula sp. A fragment from the roof of coal No. 1, 

 Seville, 111. 



Lingula Meeki Herrick. From the Cuyahoga shale of the 

 Waverly group at Ritchfield, Summit Co.,' Ohio. 



Lingula delta Hall ? A form from the Chemung group at 

 High Point, New York, much resembling in shape L. delta of 

 the Hamilton series, but which may prove to belong to Z. 

 SGutella. Also another unidentified Lingula from the Che- 

 mung of New York, possibly the same as the one just men- 

 tioned. 



Finding in the same stratum and preserved in the same way 

 two Lingulas like L. spatulata and L. Williamsana, the one 

 apparently im punctate, the other very strongly punctate, leads 

 to the conviction on one hand and the suspicion on the other 

 that the difference is not due to difference of preservation and 

 is more than one of degree, or, if only so, is sufficiently marked 

 to have more than specific significance. This is especially true 

 where the character is coupled, as in this case it appears to be, 

 with a characteristic geologic range. 



It is unfortunate that the muscular and visceral impressions 

 of Lingulipora, as in most Linguloid shells, are unknown, but 

 when ascertained it is probable that individuality in these par- 

 ticulars will be found correlated with its peculiar shell structure. 

 It might be urged that inasmuch as in all known particulars 

 except this one, Lingulipora is closely similar to Lingula, which 

 is really so individual a type compared with most other 

 Brachiopods of the same periods, it should not be separated 

 from the latter even as a subgenus. On the other hand, this 

 character (punctate shell structure) has been and would now be 

 used as a diagnostic of full generic value in any other type of 



* A single specimen identified as L. curia Conrad? from the Modiolopsis beds 

 of the Trenton formation at Frankfort, Ky., has the semblance of being punctate. 

 or at least finely pitted over portions of its surface, but I suspect this to be an 

 effect of weathering, or to arise from some other adventitious cause. 



