458 Mr. W. Lonsdale on the Genus Lithostrotion. 



lastrea (Styl. irregularis) ; and he states that it " is remarkable 

 for the nearly perfect transverse chambering of the central area ;" 

 a character delineated however to a certain extent in the Russian 

 fossil Styl. inconferta (op. cit. pi. A. figs. 2, 2 a), but believed 

 not to be persistent. Prof. M'Coy * has further described another 

 carboniferous basalt iform genus, Stylaxis, also composed of ad- 

 jacent, polygonal, easily separable tubes; and it is distinguished 

 by having, " 1st, a thin, flat, straight axis ; 2nd, a broad inner 

 area composed of numerous curved, vesicular plates in irregular 

 rows converging upwards to the axis ; 3rd, an outer area com- 

 posed of smaller and more curved vesicular plates in rows incli- 

 ning obliquely upwards and outwards." The mode of increase 

 is likewise fissiparous (op. cit. woodcut, p. 119. fig. a). Two spe- 

 cies are described, and one of them, Stylaxis Flemingi, is regarded 

 by Prof. M'Coy as probably the Lithostr. striatum of Dr. Fleming ; 

 but he considers that authority to be wrong, in referring to 

 Lhwyd and Parkinson's fossils as specifically identical with that 

 noticed in the ( British Animals."' In the ' Archives du Museum 

 d'Histoire Naturelle' other species of Stylaxis are mentioned, 

 and one of them, Styl. Portlocki, is stated to occur in the carbo- 

 niferous series of Wales (Carbonifere, Galles, p. 453). Nema- 

 phyllum arachnoideum of Prof. M'Coy is also transferred to the 

 genus (op. cit. t. v. p. 454). 



The reader has thus had brought under his attention the fol- 

 lowing basal tiform corals found in the carboniferous limestone of 

 England, independent of the species of Stylaxis mentioned in the 

 ' Archives' : — 



1. Lhwyd's Lithostrotion sive Basaltes minimus striatus et stel- 

 latus. 



2. Parkinson's Welch fossil, identified by him, but on insuffi- 

 cient evidence, with Lhwyd's Lithostrotion. 



3. Dr. Fleming's Lithostr. striatum, considered by that autho- 

 rity as equivalent to both the preceding fossils, a determination 

 regarded as doubtful. 



4. Mr. J. Phillips's Cyathophyllum hasaltiforme, identified in 

 the c Geology of Yorkshire ' with Parkinson and Fleming, but 

 for the reasons before given believed to be distinct. 



5. Prof. M'Coy's Stylastrea irregularis. 

 6. Stylaxis major. 



7. Flemingi, regarded by Mr. M'Coy 



as possibly the Lithost. striatum of Dr. Fleming. 



Each of these fossils possesses the striated and stellated cha- 

 racters mentioned by Lhwyd in his definition, if such it can be 

 considered; each of the latter six might therefore with equal 



* Ann. and Mag. Nat. Hist. 3 2nd Series, vol. iii. p. 119 et seq., Fe- 

 bruary 1849. 



