LliCANOCRINIDAE 137 



Poteriocrinus pisiformis for comparison with specimens from the Wisconsin Niagaran re- 

 sembling his Cyathocrinus pusillus, and afterward made a similar comparison in the 28th 

 Report ; he was much struck by the apparent structural resemblance, which was afterward 

 confirmed notwithstanding the errors of Roemer's description. Wachsmuth and Springer 

 followed Meek and Worthen in 1879, but called attention to the fact that the arms were 

 unknown in the species. It was not until several years later when Wachsmuth, collecting in 

 Roemer's old territory in western Tennessee, found a number of specimens of this species 

 (among them one with perfect arms, PI. I, figs. 14a, b) , that we saw that it does not belong 

 to the Inadunata at all, but falls readily under the genus Lecanocrinus, to which we referred 

 it in 1885. 



In 1891 however, S. A. Miller, having a desire to make a new species out of a specimen 

 from Tennessee placed in his hands, which he thought might conflict with the one already 

 well-known from that region, proceeded to get rid of Roemer's species by casting it out of 

 the genus, criticising Hall's allusion to it, and incidently taking a shot at his especial bete noir, 

 Wachsmuth, whose " late reference of it to Lecanocrinus," he declared, " seems to have been 

 without any consideration." His objection was that P. piriformis was described with " only 

 a single azygous interradial." If we were to stand upon a pure technicality and lay aside 

 common sense, we might admit that Miller's contention was tenable, but this is not necessary. 

 In the condition of preservation in which this small species is usually found the sutures are 

 often difficult to see, especially those toward the base, and it so happened that Roemer, out of 

 the four specimens which he had, either failed to observe the radianal for this reason, or had 

 a specimen for his description and figures which was in the precise condition of two of the 

 abnormal specimens that I have above mentioned, viz., without any radianal. And to make 

 the confusion worse, he mistook cracks in the base for sutures where none existed, and evolved 

 a base with five plates instead of three. Nevertheless if any one will take Roemer's figures 

 (of which I reproduce the two important ones, PI. I, figs. 30a, b) and compare them with 

 a set of the specimens as commonly found in the type locality (such as I have illustrated under 

 this species) he will see that beyond the least question the fossil which Roemer was attempt- 

 ing to describe was the same as this. 



It may be added for the completion of this history that Miller in this case was hitting at 

 the wrong head. He was dealing with a specimen from the Waldron shales at Newsom, and 

 the species he should have been afraid of was L. pusillus, with which his specimen is clearly 

 identical (PI. I, figs. 12, 13), although L. pisiformis is also found occasionally in the shales 

 at that locality. 



L. pisiformis, like many small and simple forms, had a long life, ranging sparsely from 

 the Laurel limestone through the Waldron shales into the Louisville limestone ; but it seems 

 to have culminated in the lower part of the Brownsport limestone of western Tennessee, where 

 it occurs abundantly at one locality near Decaturville. It also has a wide geographical range, 

 following the species of Pisocrinus with which it is associated through Tennessee, Kentucky, 

 Indiana, and New York. There is a small species of about the same size and general form 

 found among the casts in the Racine dolomite of the Chicago area which is probably the 

 same, but specimens of it are too imperfect to figure. 



Types. Roemer's original specimens are in the Mineralogical Museum at Breslau, Ger- 

 many. These figured now for the correct definition of the species are in my collection. 



Horizon and locality. Silurian, Niagaran Group, Laurel to Louisville, but chiefly in the 

 Brownsport limestone ; Decatur County, Tennessee ; near Louisville, Kentucky ; Waldron 

 and St. Paul, Indiana ; Lockport, New York ; Chicago, Illinois ; Racine, Wisconsin ; and 

 St. Mary's, Missouri. 



