NO. 1850. KNOBSTONE CRINOID FAUNA— SPRINGER. 191 



A close comparison with actual specimens from the English Lower 

 Carboniferous may show some of the above forms to be indistinguish- 

 able from them by the calyx alone. It is interesting to note in pass- 

 ing that the only American Platycrini having a long anal tube like 

 P. laevis of the English and Irish Mountain Limestone, as figured by 

 Austin, are one from the Lower Burlington and one from the Lower 

 Carboniferous beds in Nevada. The best known and best preserved 

 species of the Burlington and Keokuk have nothing of the kind. 



WACHSMUTHICRINUS Springer. 



1. W. spinosulus (Miller and Gurley). Described as Ichthyocrinus, 

 and said by the authors^ to have been "found in Clark County, 

 Indiana, in what is called the Knobstone, but which we think must 

 be of the age of the Keokuk Group." 



Locality. — Several specimens are from Stone's farm, Clark County, 

 Indiana, and JMr. Greene informs me that the type was found by him 

 at the same place. 



2. A smooth form, without nodes or spines, undescribed, from 

 the same locality, and also from the KJnobstone beds in the neigh- 

 borhood of Junction City, Kentucky, along the outcrop eastward 

 from Lebanon. 



This genus is characteristically Lower Burlington, a single speci- 

 men only being known from the upper bed. It occurs also at Fern 

 Glen, Missouri, Lake Valley, New Mexico, and in the Mountain Lime- 

 stone of England. 



MESPILOCRINUS de Koninek and Lehon. 



Good specimens of two new species at Button-mould Knob and at 

 Stone's farm; also stem fragments at Fern Glen, Missouri. The 

 genus occurs in the Mountain Limestone of Belgium and England, 

 and in the Lower and (rarely) Upper Burlington Limestone at 

 Burlington, and in the Choteau of Missouri. It is a highly special- 

 ized form, and no trace of it has ever been seen in the Keokuk rocks. 



METICHTHYOCRINUS Springer. 



1. M. tiaraeformis (Troost, Hall). Described as Ichthyocrinus, 

 and the horizon is stated by Hall, Wachsmuth and Springer, and 

 Miller, simply as the Subcarboniferous. Oral tradition has always 

 assigned it to the Keokuk, and in the republication of Troost's 

 Monograph^ the horizon is given as the "Keokuk horizon of the 

 TuUahoma formation." The type is from Wliites Creek, of a 

 rather neutral, or dirty yellowish color. I have another almost 

 identical with it; one of a more reddish color; and two of a decided 



1 Bull. Illinois State Mus., No. 5, p. 45. » Bull. 64, U. S. Nat. Mus., p. 100. 



