1912] The Ottawa Naturalist. 79 



along the top of each arm, while the greater part of the surface 

 is covered with small convex triangular plates. Miller found 

 the plates to be spine-bearing, a point which can not be definitely 

 decided in the present species. From the photograph it appears 

 that there are spaces between the small triangular plates on the 

 abactinal surface in Palaaster? magnificus, while in P.? wilsoni 

 these plates actually overlap each other. 



There is a superficial resemblance between Palceaster? 

 wilsoni and Urasterella pulchella (Billings), but the latter species 

 does not have the double row of marginal plates, nor the large 

 plates along the top of the arm. The arms are also much more 

 slender in Billings' species. 



Of course the reference of this species to Pales aster is, purelv 

 a convention, as it has nothing in common with the type of the 

 genus. The generic position of these starfishes will be discussed 

 in the monograph by Professor Schuchert, which it is expected, 

 will appear at an early date. 



Locality and formation. The holotype was found by Miss 

 A. E. Wilson in a fence near the large quarry in the Lowville 

 formation at City View, a short distance south-west of Ottawa. 

 While the Lowville is the only formation which is exposed at 

 this particular spot, the starfish seems to have been derived 

 from the Black River, which outcrops only a short distance 

 awav. The matrix contains, beside the starfish, Rhynchotrema 

 inoequivalve (shown in the photograph), Orthis tricenaria, and 

 Rafinesquina alternata. The species is dedicated to its dis- 

 coverer, whose private collection contains the type. 



GENUS MARIACRINUS HALL. 

 MARIACRINSUS ? INSUETUS, SP. NOV. 



Mariacrinus sp. Raymond, 1907. American Journal of 

 Science, Fourth Series, Vol. XXIII, p. 118. 



Two fragmentary calices of crinoids from the Three Forks 

 Shale at Logan, Montana, are of importance, as they are the only 

 crinoids thus far known from the Devonian of the Rocky 

 Mountains. These fragments were sent to Mr. Frank Springer 

 for identification, and he reported that they probably belonged 

 to the genus Mariacrinus. 



One fragment (Figure 1) retains the base of a calyx and 

 fragments of four radials. All sutures are obliterated, but 

 the ornamentation makes possible the determination of the 

 probable outline of the plates. From such parts as remain, 

 the radials seem to have been in contact. The position of the 

 two notches in the margin of the area of stem attachment suggest 

 that there are four basals, though there may be only three, two 

 large and one small. The ornamentation consists of raised lines 



