57 



plate between tho tulx' for the orilicc ami the azygous area. 

 Notwith stand iiifj these peculiarities, we have no doubt that we 

 ai-e correct in ]>lacing the azyKO"^ area between the foui- 

 armed rays. Tiiere are four ovarian ajx-itui'es between eacli 

 of the rays and two between each of the arms which arrange- 

 ment gives to the species forty- four ovarian aperture.s. 



This is a remarkable and extraordinary species readily dis- 

 tinguished from all others, though at lirst glance resembling 

 D. vasculitni and having the arm formula of D. hellulu:^, 4-|-3+3- 

 + i>4-4, a species with wliicii it agrees in no other )-espect. It 

 is not abnormal. 



Found by George K. Greene in the Hamilton Group, near 

 Cliai-lestown. Tmliana, now in tlie collection of Wm. P. E. Gurley. 



Family TAXOCRINID.F.. 



FOUBESOL'lilNUS (J KEEN EI, U. sp. 



Plate IV, Fkj. 25, ozyuous side vieio: Fifj. V, basal view, show 

 iiuj jiart of ihe colnmn lirokcn down. 



vSpecies very large; radial series not elevated beyond the 

 interradial ai-eas; plates tlatteued or slightly convex; sutures 

 beveled. The phites do not overlap, as is usual in this genus, 

 nor does the column tajjer as rajiidly, below the caly.x, as 

 usual. 



Basals within the calyx. Subradials wide and only partly 

 exposed. Primary radials four in each series and from two 

 to four times as wide as long. They are directed at an angle 

 of about 4."> degrees, so as to give the lower side of the calyx 

 a bi'oadly loundcd outline, that is continued into tho tertiary 

 series of plates where {ho calyx has its greatest diameter. 

 The last jiriinary radial in eacli series is long(>r tlian those 

 below it, pentagonal, axillai-y, and has rathei- steep upper 

 sloj)ing sides n]ion which it supports the secondary radials. 

 Thei-e are three secondary I'ailials in each of eight series and 

 two in tlie otiier two series. Tlie proxinuil series on tlie left 

 of tln> a/.ygous area has only two secondary radials and the 

 distal series, in the ray, on the i-iglit of the azygous area, has 

 only two secondary I'adials. The secondary radials, thoni;]i of 

 unequal siz(\ are not mucji smaller than the primai'y radials. 



