June, 1906. Hypsocrinus — Springer and Slocom. 269 



mens of this species, from the same locality as Oehlert's, which show 

 them very plainly, not as actual sutures, but rather as lines of 

 anchylosis. So it is evidently a constant character. The trans- 

 verse bisection of the radials by the sutures represented by these 

 lines would produce compound radials in the same rays in which 

 they occur in Haplocrimis, Heterocrinus, and similar forms. This 

 species, therefore, represents a form which in its younger stage would 

 have fallen into the same group of irregular crinoids as our genus, 

 but in which, by growth during life, the compound radials were 

 eliminated, and the Crinoid modified into a regular form. Phimo- 

 cri nits has straight radial facets, filling the entire distal face of the 

 radials, and the arms articulate on a linear hinge line. 



Hypsocrinus fieldi sp. nov. PI. LXXXI, Figs. 1-6. 



Calyx elongate, cylindrical, slightly expanding to the arm bases. 

 Base truncate; basal facet broad, slightly concave, entirely filled by 

 the column; axial canal stellate or pentagonal, interradial in posi- 

 tion. Basals very elongate, forming two-fifths to half the height 

 of the cup. Radials, three large and two small, all arm-bearing; 

 the two smaller ones short, wider than high, separated from the 

 basals by three much more elongate infer-radials, one of which is 

 directly beneath the right posterior radial, and represents the 

 radianal; the other two are for the most part directly under the 

 right anterior radial, whose lower margin meets them by an obtuse 

 angle, but in part obliquely under the left lower corner of the 

 anterior radial, meeting it by a curved suture; the other three 

 radials are large and elongate plates. Arm facets very shallow, 

 curved, not entirely filling the distal face of the radials, but leaving 

 short, sloping shoulders between, which are rounded off exteriorly, 

 but probably formed a support for oral plates in the tegmen. Arms 

 simple, uniserial, tapering rapidly, and doubtless very short. No 

 trace of a dorsal canal in radials or brachials. Anal structures and 

 tegmen unknown. Surface smooth; calyx plates slightly rounded, 

 and sutures distinct. Stem unknown ; but it was large at the proxi- 

 mal end, as the radiate markings of its articulation are visible to the 

 edge of the basal facet. 



Horizon and Locality: Devonian; Hamilton group. Found near 

 East Bethany, New York. 



The specific name is in memory of Marshall Field, the founder of 

 the Field Columbian Museum, where the type specimen is deposited. 



Remarks. In the foregoing description we have found it neces- 

 sary to guard against the insertion of some details, which are appar- 



