45:3 Mr. W. Lonsdale on the Genus Lithostrotion. 



of detailed information, omitting among essentials simply the 

 mode of developing additional corallites or columns. His 

 figures and description, however, can be compared with 

 Lhwyd's delineation only as regards the mode of aggregation, 

 the form and exterior characters of the columns, and the 

 many rays. It is also probable that Lhwyd's fossil possessed 

 equally with that of Parkinson a facility in breaking into 

 small masses or single corallites ; but whether the original 

 Lithostrotion had an internal structure similar to that of the 

 coral identified with it, must be a conjecture. Following the 

 literature of the genus as accurately as possible, the next autho- 

 rity, accompanied by a description *, which can be quoted is 

 Dr. Flemirngt, and he is believed to be the first naturalist who 

 assigned a place to Lithostrotion in a system of zoology. He 

 describes four species: 1. L. striatum; 2. L. floriforme ; 3. L. ob- 

 longum; and 4. L. marginatum. The first is identified with 

 Lhwyd and Parkinson's delineations ; but " the rays of the star" 

 are stated to " unite with a small, solid, central axis " {op. bit. 

 p. 508) ; the second species, L. floriforme, is founded on the Der- 

 byshire fossil represented by Martin J, and designated Erismato- 

 lithus Madreporites (ftoriformis) ; and it is said by Dr. Fleming 

 " to differ chiefly from L. striatum in its greater size, and the 

 axis occupying a greater space ;" he quotes also the following 

 statement of Martin — " centres projecting, pointed and writhed 

 or twisted like a rope §." The third species, L. oblongum, is the 

 well-known oolitic Tisbury coral, figured by Parkinson ||, whose 

 delineations are cited; and the fourth, L. marginatum ) is a moun- 

 tain limestone fossil of which Dr. Fleming had seen only " two 

 detached columns M (p. 508). The present inquiry is necessarily 

 limited to the first two species. 



* In the ' Outlines of the Geology of England and "Wales/ by the Rev. 

 W. D. Conybeare and Mr. W. Phillips, Lhvvyd's figure is quoted under the 

 designation Astrea basaltiformis (p. 359, 1822), but no description or rea- 

 son for a changed generic determination is given. 



f History of British Animals, p. 508, 1828. 



% Petrificata Derbiensia, tab. 43. figs. 3 & 4 ; also tab. 44. fig. 5? 1809. 



§ The Derbyshire fossil figured by Guettard is probably this species, and 

 the peculiar detached flower-like character of the terminations to the coral- 

 lites is stated in an extract from a catalogue to be due to the decomposition 

 of the cellular tissue — " la plupart sont evides par la decomposition de leur 

 tissu cellulaire, ce qui les rend semblables a des fleurs en entonnoir, garnies 

 de leur pistil." (Memoires, &c. t. iv. of the complete series, or t. i. Nouvelle 

 Collection, p. 75. pi. 30, 1786.) 



j| Org. Rem. t. ii. p. 56. tab. 6. figs. 12, 13. The fossil has been recently 

 named Isastrea oblonga by M. Milne-Edwards and M. J. Haime, Archives 

 du Mus. d'llist. Nat. vol. v. p. 103, 1851 ; also volume of the Pakeonto- 

 graphical Society for 1851, Description of British Fossil Corals, Part 2. 

 p. 73-75. 



