152 THE CRINO1DEA 



reminiscent of Calycanthocrinus ; here, however, the RR are axillary, 

 and PR not developed. Rowley (1895) has described calyces less than 

 5 mm. high. FAMILY 10. SYMBATHOCRINIDAE. Monocyclica Inadunata, 

 with 5 simple RR, bearing 5 unbranched, non-pinnulate arms, which rest 

 as a rule on broad articular facets projecting adorally in "muscle -plates," 

 corresponding to the muscle-fossae. Genera Phimocrinus (Low. and Mid. 

 Devonian, Europe), Stylocrinus and Stortingocrinus (Mid. Devonian, Europe), 

 Symbathocrinvj, including Lageniocrinus, which is probably its young (Upper 

 Devonian and Lower Carboniferous, Europe and N. America). Phimocrinus, 

 Schultze (1866), is primitive in having 5 BB, while all the rest have 3 ; 

 the oldest species, P. Jouberti, Oehlert, shows clear traces of horizontal 

 suture in r. post., r. ant, and 1. ant. RR, the usual compound RR of typical 

 Heterocrinidae ; the proximal plate of the anal tube is placed as in those 

 forms. The latter feature is also found in Stortingocrinus, Schultze (1866), 

 which is notable for having the small unfused B in 1. post. IR, and the 

 angles of the columnar canal radial in position, though the genus is Mono- 

 cyclic. Stylocrinus, Sandberger (1850), has no facet on RR for support 

 of an anal tube, nor is the usual passage for the rectum seen in the cup- 



RR 



Fm. LXV. 



Dissection of cup of Xi/mbathocrinuf. The projections on the llll are muscle-plates. 



wall ; therefore one cannot orient the small B ; the anus probably pierced 

 post. O. Symbathocrinus, Phillips (1836), has small B in 1. ant. IR, as in 

 Platycrinidae ; the anal tube rests on the shoulder of r. post. R ; 5 O, 

 all small, post. O being the largest and separated from the muscle-plates 

 of the adjacent RR by the passage of the rectum (Fig. LXV.). The family 

 is not clearly denned, and its Middle Devonian members present remarkable, 

 though superficial, resemblances to the contemporary Cupressocrinidae. 



FAMILY 11. BELEMNOCRINIDAE. Monocyclica Inadunata, with 5 

 BB, 5 simple RR, each supporting by a slightly excavate facet an arm 

 which forks on IBr 4 or 5 ; each ramus, with numerous syzygies in the 

 proximal portion, bearing ramuli on alternate sides of most epizygals 

 and of all ordinary distal brachials ; single narrow anal in radial circlet, 

 resting on post. B, and supporting a large anal tube composed of alter- 

 nating hexagonal plates, folded on their lateral margins. Genus Belem- 

 nocrinus, White (1862), Lower Carboniferous, N. America. Dorsal cup 

 elongate, its plates solid, and thecal cavity a narrow canal below and 

 shallow excavation above, thus resembling that of many Neozoic crinoids. 

 B. typus has no cirri on the stem, which is circular in section ; B. florifer 

 has a stellate stem of true Monocyclic type, with 3 or 4 cirri to each node. 



