G CATALOGUE OF THE BLASTOIDEA. 



Several species of Pentremites (or rather Pentremitidea) from the Eifel were 

 described by Schultze x in 1S66 ; and Granatocrinus was formally adopted by Meek 

 and Worthen 2 in the same year. Two years later they suggested the name Tricce- 

 locriinis for a remarkable type allied to Troostocrinus 3 ; and in 18G9 they proposed 

 to establish a new genus, Codonites 4 , for the Pentremites stelliformis, Ow. & Shum., 

 which (though unknown to them) had already been taken by Von Seebach as the 

 type of Orophocrinus. They also confirmed White's observations respecting the 

 closure of the summit-openings by additional plates, which likewise extend down 

 the ambulacra so as to cover them in and convert them into tunnels. In this year, 

 too, Billings 5 began the publication of a very striking series of papers on the 

 structure of Crinoids, Cystids, and Blastoids, in which he devoted a good deal of 

 attention to the morphology of Pentremites, Cadaster, and Elceacrinus. The remark- 

 able lamellar tubes beneath and between the ambulacra, which appear to have 

 served the function of respiration, were designated by him as " hydrospires," and 

 the summit-openings in connection with them were called " spiracles," names which 

 have since been generally adopted. 



In 1873 several excellent figures of Blastoids were published by Meek and 

 Worthen ti ; but they were unfortunately not accompanied by any connected 

 description of the morphological details which they illustrated so well. 



Three years later an attempt was made by Mr. R. Etheridge, Jun., 7 to elucidate the 

 structure of Austin's little-known genus Astrocrinites on the basis of a new species 

 discovered in the Scotch Carboniferous shales ; and he subsequently described, under 

 the general name Pentremites 8 , an imperfectly-preserved fossil from the same horizon, 

 which has since proved to belong to Phcenoschisma. Many important observations 

 on Blastoid morphology were published incidentally by Wachsmuth in his " Notes on 



1 " Jlonographie dor Echinodermen des Eiflerkalkes." Denkschr. k. Akad. Wiss. Wieu, lid. xxvi. 1806, 

 pp. 111-1 J 4. 



- '■ Contributions to tho Palaeontology of Illinois and other Western States." Proc. Acad. Nat. Sci. Pbilad. 

 L866, p. 257. 



: •• Remarks on some types of Carboniferous Crinoidea, with Descriptions of new Genera and Species of 

 the same and of one Echinoid." Ibid. 1868, p. 356. 



1 " Remarks on the lilastoidea, with Descriptions of New Species." Ibid. L869, pp. 83-01. 

 •■ Noti ,- on the Structure of the Crinoidea, Cystidea, and lilastoidea." American Journ. Sci. vol. xlviii. 

 1869, pp. 69 83; vol. xlix. 1870, pp. 51-58; vol.1. 1870, pp. 225-240; Ann. & Mag. Nat. Hist. 1870, 

 vol. x. pp. 251 266 ami 409-416; vol. vii. 1871, pp. 142 158. 



' Report, Geological Survey of Illinois, ls73, vol. v. pis. viii., ix. 



■ •■ On the Occurrence of the Genus Astrocrinites (Austin) in the Lower Carboniferous Limestone Scries 

 ol Scotland, with the description of a new species (A. /!■ nnii i) and remarks on the Genus." Quart. Journ. 

 Geol. Soc. L876, vol. xxxii. pp. 103-115, pis. xii., xiii. 



~ f On the Occurrence of the Genus Pentremites (Say) in the Carboniferous Limestone Series of the East 

 cotland; and Notes on Carboniferous Braehiopoda." Proc. Nat. Hist. Soc. Glasgow, l s -4. vol. iv. 

 pp. 260 263, pi. v. 



