. The Canadian field-naturalist. Natural history. Figure 1 X 2. Figure 2x2. The other specimen is a part of the dorsal cup, lacking the basal portion. Figure 2 shows this fragment, the ray lacking the distichial being the anterior radius. The rays show a strong longitudinal ridge crossing the first costal and bifurcating near the centre of the second, sending a branch onto each of the dis- tichials. This species appears to agree with Mariacrinus warreni from the Niagara in having only two distichials, and no palmers in the calyx. In fact, none of the rays show more than one cycle of distichial
. The Canadian field-naturalist. Natural history. Figure 1 X 2. Figure 2x2. The other specimen is a part of the dorsal cup, lacking the basal portion. Figure 2 shows this fragment, the ray lacking the distichial being the anterior radius. The rays show a strong longitudinal ridge crossing the first costal and bifurcating near the centre of the second, sending a branch onto each of the dis- tichials. This species appears to agree with Mariacrinus warreni from the Niagara in having only two distichials, and no palmers in the calyx. In fact, none of the rays show more than one cycle of distichials, but there were probably two when the specimen was complete. The interradial areas are not depressed as in most species of this genus, a section through the calyx at the second cycle of interbrachials being almost circular in outline. There is, however, a slight depression in the interdistichial spaces. The first interbrachial is large, the next two slightly smaller. The three plates of the third series and the four of the fourth are not regularly hexagonal, but laterally compressed. The posterior interradius is very badly preserved, but there appear to be five interbrachials in the third row. As shown in the figure the plates are ornamented with raised lines connecting the centres of the plates. Locality.—The specimens were found by the writer in the limestone of the Three Forks Shale at Logan, Montana, asso- ciated with the fossils of the brachiopod facies of the Clynienia americana fauna. The types are in the Carnegie Museum, Pittsburgh, Penna. GENUS SCHCENASTER MEEK AND WORTHEN. SCHOENASTER? MONTANUS SP. NOV. Animal small, about an inch in diameter. Rays short, slender, extending about one-half their length beyond the disk. Disk large, pentagonal, the margin slightly concave between the rays. The five proximal plates of the adambulacreal series function as orals, while on the arms bevond the disk the adam-. Please note that these images are extracted from scanned page i
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