. The Annals and magazine of natural history; zoology, botany, and geology. Natural history; Zoology; Botany; Geology. 198 Mr. F. A. Bather on British Fossil Crinoids irregular and numerous, as in Botryocrinus, but appear to be more or less alternating- (zincotype, figs. 3 and 4). The total length of the arms in 57048 is 11 centim. 1J, the usual number being 8. their width 3 millim. I Br number from 7 to Their height is 1*4 millim. II Br 9, 10, or 11. III Br from 9 to 14. IV Br from 12 to 26. V Br numbers noted 17 and 22. VI Br numbers noted 16 and 25. VII Br 15 observed. VIII Br and IX B
. The Annals and magazine of natural history; zoology, botany, and geology. Natural history; Zoology; Botany; Geology. 198 Mr. F. A. Bather on British Fossil Crinoids irregular and numerous, as in Botryocrinus, but appear to be more or less alternating- (zincotype, figs. 3 and 4). The total length of the arms in 57048 is 11 centim. 1J, the usual number being 8. their width 3 millim. I Br number from 7 to Their height is 1*4 millim. II Br 9, 10, or 11. III Br from 9 to 14. IV Br from 12 to 26. V Br numbers noted 17 and 22. VI Br numbers noted 16 and 25. VII Br 15 observed. VIII Br and IX Br are so small and faint that it is difficult to make out their exact numbers. The width of the finials is about '25 millim. The distal portions of an arm-branch are figured here (fig. 6), to show that there is no suspicion of pinnules. Anal structures. — Anal x is hexagonal, resting on the hori- zontal upper side of post. B, in a line with RR, and supporting three plates, viz. a median proxi- mal plate of similar shape and a small plate on either side be- „. ^ ,r , .. l -, ., ,. ,. , Fig. 9.—M. lorens. tween it and the adjacent radials {rt and It). The Ventral Sac in 57048, where it is magnificently displayed, has a length centim. At its origin it is 10 millim. wide, but increases to 13 millim. and then decreases very gradually, is transversely compressed and is very flat. In its plan of structure this sac resembles those of Thenaro- crinus, Botryocrinus, and Dendrocrinus (what may be called the wickerwork-type, Trautschold's u Angulosi "). Seen from the posterior, 5 ridges are visible, which are from left to right as follows :—(1) ridge starting from It, (2) ridge starting from a plate intercalated between It and median proximal plate, (3) median ridge, starting from median proximal plate, (4) ridge starting from rt} (5) ridge on right of rt ridge. There are probably three other ridges on the anterior side. This would make the number of ridges 8 in all, in which
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