Turbinolia. ZOOPHYTA. LAMELLIFERiE. 50i) 



249. Two specimens found in 1809, growing on a dead valve of Pec- 

 ten opercularis, from deep water off Foulah, in Zetland. 



The largest specimen is inversely conical ; a little compressed ; half an inch 

 in height ; two-tenths, in its broadest diameter at the base, and six-tenths at 

 the star, where it is four-tenths across ; externally it is longitudinally striated 

 and rough. The disc is oval, and a little compressed. The lamella? are dis- 

 posed in fours, and may be distinguished into three different kinds. The first 

 are the highest and the broadest at the margin, but as they descend into the 

 disc they become narrower before they join the central plate. The second 

 kind are narrower than the preceding at the margin, but towards the middle 

 they suddenly enlarge and join the middle plate. The third kind are the 

 smallest, and terminate before reaching the middle plate. The space included 

 between a pair of the first kind of plates, contains one of the second kind in 

 the middle, with one of the third kind in each of the lateral spaces. Those 

 on the sides are rough, with small scattered tubercles, and their margins are 

 curled. This last circumstance occasions the roughness externally, where the 

 longitudinal strire are the remains of the gills. The plate which occupies the 

 bottom of the concavity is smooth, various twisted, and connected with the 

 base of the lateral plates. When first observed, the disc was covered with 

 black putrid animal matter. — It has been reported that the C. musicalis (Ellis, 

 Phil. Trans. 1/G3, t. xx. f. 14.) has been cast ashore on the Irish coast. 



EXTINCT SPECIES. 



1. C. annularis. — Branched, nearly cylindrical, with transverse plates, which 

 exteriorly seem like a series of ligatures ; surface not muricated. — Madrepo- 

 rite, Park. Org. Rem. ii. G"J. t. v. f. 5. — In Oolite. 



2. C. fasciculata. — Crowded, branched, round, nearly cylindrical, slightly 



flexuous, and about a quarter of an inch in diameter Madreporite, Park. 



Org. Rem. 51. t. vi. f. 8. — Madrepora cespitosa, Marl. Derb. t. 17 Carboni- 

 ferous Limestone. 



3. C. duplicating Tubes cylindrical, adjacent, unequal ; centre proliferous ; 



margin dilated Madrepora dup. Mart. Pet. Derb. t. xxx. — Carboniferous 



Limestone. 



4. C. affinis Stems slightly branched, cylindrical, equal, smooth, rather 



distant, and about half an inch in diameter. — M. aff. Mart. Derb. t. 31 — Car- 

 boniferous Limestone. 



5. C. juncea Stems slightly branched, cylindrical, smooth, or slightly 



wrinkled transversely, and about one-tenth of an inch in diameter.— Junci 

 lapidei, Ure, Ruth. 337- t. xix. f. 12— Very common in. Carboniferous Lime- 

 stone. 



G. C. centralis Root spreading, indented ; stem narrow at the base ; en- 

 larging subcylindrically towards the tip ; longitudinally striated ; the striae 

 alternately larger and smaller ; no transverse stria? ; disc with small and large 

 plates from the circumference to the centre — Corallite, Park. Org. Rem. ii. 

 32. t. iv. f. 15, 10. — Madrepora centralis, Mant. Geol. 159. t. xvi. 1. 2, 4 — In 

 Chalk. 



It is probable that Amplexus coralloides, p. 251. though inserted by Mr 

 Sowerby among the multilocular testacea, may yet be found connected with 

 the piesent genus. 



Gen. XXX. TURBINOLIA.— Turbinated, detached, base 

 acute, not adhering ; star single. 

 71. T. borealis. — Widely conical, slightly bent. 



