180 Beports and Proceedings — 



independently created, or whether it was real, consequent on the 

 incoming of species by secondary law. In any case the lost Rep- 

 tilian structures dealt with in the present paper are now manifested 

 by quadrupeds with a higher condition of cerebral, circulatory, 

 respiratory, and tegumentary systems, the acquisition of which, the 

 author thought, is not intelligible on either the Lamarckian or 

 Darwinian hypotheses. 



2. " On the Occurrence of the Genus Astrocrinites, Austin, in the 

 Scotch Carboniferous Limestone Series, with a Description of a 

 ]Sew Species (A.? Benniei), and Remarks on the Genus." By R. 

 Etheridge, Esq., jun., F.G.S. 



The author, in his introduction to the paper, commenced with a 

 general history of the genus Astrocrinites of Austin, commenting 

 upon the change of name it had received from the several authors 

 who had written upon and noticed the species A. tetragomis of 

 Austin. 



In 1843 Major T. Austin described this Aberrant Echinoderm under 

 the name Astrocrinites, assigning its geological horizon to the 

 Carboniferous Limestone, and locality Yorkshire. 



Dr. H. G. Bronn rejected the name Astrocrinites on acconnt of 

 its resemblance to Aster ocrinites of Miinster, and proposed instead 

 that of Zygocrinus. Romer, from the four-rayed structure of our 

 Astrocrinites. allied it to the Cystoidea rather than to the Blastoidea. 

 Prof, de Koninck and M. le Hon, however, referred Zygocrinus to 

 the Blastoidea, and stated their reasons for so doing. Prof. Morris 

 in 1854 altered Austin's Astrocrinites into Astrocrinus, and does not 

 notice Bronn's name Zygocrinus. Prof. Pictet provisionally referred 

 the latter genus structurally to Codonaster, noticing, however, its 

 four instead of five pseudambulacra. The author then notices at 

 some length the species he proposes to call A. Benniei, which appears 

 to differ much from Austin's A. tetragonus. The body or calyx of 

 A. Benniei is tetraradiate, having four convex lobes, three of which 

 are alike, the fourth differing considerably from the others, the deep 

 re-entering angles between the lobes are occupied by the pseudam- 

 bnlacra, the dorsal surface is densely covered with closely set tuber- 

 cles, but shows no point of attachment, the ventral surface is flat- 

 tened, having a large central aperture, from which radiate tlie four 

 pseudambulacra ; excentric as compared with the ambulacral system 

 is a second and pyriform aperture of complex structure. The com- 

 ponent parts are then minutely described, followed by careful de- 

 scriptions of the pseudambulacra, apertures, and ornamentation, also 

 a discussion as to the presence of a madreporiform tubercle. The 

 second part of the paper treats upon the affinities of A . Benniei, 

 Ether., with A. tetragonus, Austin. Part the third enters fully 

 and critically into the systematic position oi Astrocrinites amongst 

 the Cystoidea and Blastoidea. In the concluding and fourth por- 

 tion of the paper, the localities and geological horizons are given. 

 Twenty- seven figures, occupying three plates, accompanied the 

 paper. 



3. " On the Genus Merycoclioerus (Family Oreodontidse), with de- 



