516 GEOLOGY OF THE YELLOWSTONE NATIONAL PARK. 



question in being- much smaller and in having twenty instead of thirty 

 arms. The constituent plates appear to be sculptured, and to have elevated 

 margins, while this is not the case with the form referred to P. symmetricus, 

 although preservation may have obscured this character. 



I believe this species to be identical with that which White described 

 and figured as Platycrinus sp., 2 although it is impossible to be certain upon 

 this point, as neither material is very good. 



Formation and locality : Madison limestone, divide between Gallatin 

 River and Panther Creek, Gallatin Range ; head of Conant Creek, Teton 

 Range ; W. H. Weed. Kinderhook beds, Legrand, Iowa. 



SCAPHIOCRINUS Hall, 1858. 



SCAPHIOCRINUS sp. 



This form has a rather small cup-shaped calyx, about 19 mm. high 

 and 19 mm. in greatest diameter. There are five large basals, above 

 which are a number of smaller plates; but the summit of the calyx is 

 incomplete and the outline of the plates is obscured by exfoliation, so that 

 even the generic position is only approximately correct, 



Formation and locality: Madison limestone, Crowfoot Ridge, Gallatin 

 Range, bed 28; J. P. ladings and W. H. Weed. 



BRYOZOA. 



ANISOTRYPA Ulrich, 1883. 

 Anisotrypa sp. 



This genus is not yet known below the Keokuk. It is represented in 

 the Yellowstone National Park collection but from one locality and by a 

 single species. This grows in a hollow club-shaped zoarium, enlarged and 

 rounding at one end. Diameter of the branch, from 5 to 7 mm. Height 

 of the zooidal tubes, which measures the thickness of the zoarium, is very 

 slio'ht, amounting to less than 1 mm. Diameter, about 0.4 mm. The zooidal 

 tubes seem to be nearly uniform in size, and I have not been able to dis- 

 tinguish clusters of larger cells. Such may, however, exist. 



This species appears to be distinct from any known representation of 

 the genus. 



•Wheeler's U. S. Geog. Surv. W. 100th Merid., Vol. IV, 1*77, p. 81, PI. V, tig. 2. 



