II. Arbeiten von speciellerem Character etc. 1. Crinoidea. 197 



very minute, often not visible externally, and resting from within against the me- 

 dian angular process within the articulating depression of a large radial. Their 

 inner face is much larger, triangular in form, with concave sides. The arrange- 

 ment is such that these sides , together with the outer portions of the articulating 

 scar of the first plates , form two semicircular sockets , supporting each a small 

 pentagonal bifurcating secondary radial, which here, as in Pterotocrinus and Mar- 

 supiocrinus , constitutes a part of the body, and in turn supports two arms , or 

 twenty arms in all. Form of the arms unknown. Vault generally of equal height 

 with the calyx , decidedly lobed when viewed from above ; composed of numerous 

 small pieces, some of them spiniferous ; toward the posterior side obliquely flat- 

 tened, with a lateral anal aperture towards the upper end. Radial area elevated, 

 and extending outward ; interradial portions depressed, posterior side much wider. 

 Central vault piece large, nodose or spiniferous. The four large proximal plates 

 occupy in four of the interradial spaces the upper portion of the depression, while 

 the two smaller ones rest partly against the radial portions of the dome , with 

 several small anal plates and the anal aperture between them. Interradial vault 

 pieces three, rather large, and much higher than wide. The first radial vault 

 piece is spiniferous in most species, the succeeding plates small and nodose, ar- 

 ranged longitudinally in rows, forming together regular arches over the ambula- 

 cral passages within the body. There is a large elongate brachial piece between 

 the two divisions of each ray, which at its lower end connects with the upper point 

 of the second radial, thus giving origin to two arm openings in each ray. The 

 anal area has three large pieces in the first series, which rest upon the anal plate 

 of the calyx, the median one has form and size of the interradial plates, the two 

 others are smaller. In the second series there are two plates, followed by a 

 number of minute pieces surrounding the anal aperture, which is protuberant. 

 Column probably cylindrical and small, with a minute central canal. 

 Teleiocrinus nov. gen. (subfam. Actinocrinidae). Body large; calyx urnsha- 

 ped , subconical below ; the upper part , including the higher orders of ra- 

 dials , spread out horizontally , and formed into an extended , continous rim 

 around the body; vault moderately convex, with a strong subcentral anal tube ; 

 surface ornamentation similar to Actinocrinus, but, as a rule, very much coarser, 

 the nodes more prominent than the striations. and sometimes almost entirely 

 obscuring them. Basals three, large, massive, projecting beyond the point 

 of attachment for the column, and frequently extended into a bipartite node; 

 sutures deep. Primary radials 3X5; the first large, as high as wide; the 

 second generally hexagonal, of the same proportions as the first, but smaller; the 

 third like the second, but angular above instead of truncate. Secondary radials 

 t X 10, axillary, supporting the two main divisions of the ray. The radials of all 

 succeeding orders are composed respectively of a single series of pieces, of which 

 only one plate, of each main division, in each order, bifurcates again, and this 

 alternately on opposite sides, the other - - opposite - - plate which is never axil- 

 lary, being succeeded in a direct line by a row of a variable number of fixed arm 

 plates, which form branches within the body, alternately given off from the main 

 trunks. All plates of the lateral branches and main divisions are closely joined 

 with each other, and with those of the adjoining rays, and these together form the 

 peculiar rim which surrounds the body. The plates of the rim are nearly of equal 

 size, convex, and formed longitudinally into ridges, which give to the alternate 

 branches the aspect of fixed arms, which they evidently are. Arm openings large 

 and lateral, with a separate respiratory (?) pore to each opening. Interradial, 

 anal and interaxillary plates arranged as in Actinocrinus, and scarcely more nume- 

 rous, they decrease in size upward, the upper ones are very minute. Dome con- 



