ORDER V CRINOIDEA—ARTICULATA 71 
, 
not continued over the median portion of the plate. / with transverse 
ridges and large muscular fossae. Stem-joints barrel-shaped. Jaekel regards 
the centrodorsal as representing the anchylosed 6, notwithstanding the 
absence of axial canals. Upper Jura. 
Phyllocrinus, @Orb. Dorsal cup globose ; upper edges of & with narrow 
articular facets, to either side of which are long, upright projections. Upper 
Jura and Lower Cretaceous, notably in the Mediterranean district. 
Family 5. Holopidae. Zittel. 
Base monocyclic ; stemless. Dorsal cup 
beaker-shaped, and formed of five fused 
radials, by which the body was either directly 
attached, or, as was more probably the case, 
it was supported by a cycle of basals 
enclosed within the radials. Tegmen com- 
posed of five large triangular orals, sur- 
rounded by a narrow band of pertsome. a, 0, Cotylederma docens, Deslongeh. Upper Lias ; 
Arms 5x2, uniserial, strongly incwrving, May, Cevvates. Calyx sen fon above) Same 
and composed of large thick plates. fingen; Baden. ¢, Centrodorsal; d, Circlet of fused 
basals. (All figures of the natural size). 

Fic, 286. 
Of the forms belonging to this 
family, Cotylederma, Quenst. (Fig. 286), is found in the Lias; Cyathidium,Steenstr. 
(Micropocrinus, Menegh.), in the 
Cretaceous and Tertiary ; and 
Holopus, VOrb., at great depths 
in existing seas. 

Fic. 287. Family 6. Plicatocrinidae. 
Plicatocrinus hexagonus, Mist. Upper : 
Jura; Streitberg, Franconia. a, Calyx with Zittel. 
eninls and undivided base; b, c, Dorsal and ] ] 
ateral aspects of same (slightly enlarged) ; monocyclic “unnel- 
d-f, First brachial, seen from the inside, Base ED J 
outside, and from below respectively. shaped, quadrangular to heaa- 
gonal, and formed of one solid 
piece. Radials four, six, or eight 
(rarely five or seven), short and 
delicate. These support axillaries, 
which give origin to two simple 
arms composed of wedge-shaped 
ossicles and united by muscular 
articulation.  Pinnules usually 
composed of a single piece. Body- 
cavity wide and deep. 
Plicatocrinus, Miinst. (Fig. 
287). Radials comparatively 
Hyocrinus Bethellianus, Wyy. Thomson. Recent; Atlantic : 7 Seo =) Pa G ce 
Ocean. 4, Individual twice the natural size. B, Tegmen several thin, their articular facets 
times enlarged; am, Ambulacral furrows of the arms; c, Dorsal erescent - shaped : the outer 
canals ; an, Anus; m, Mouth; o, Orals (after Wyville Thomson). 5 Be 
faces longitudinally convex. 
Pinnules undivided, except the proximal ones, which consist of three pieces ; 
they are angtflar or keel-shaped along the dorsal side, and deeply furrowed 

