292 Messrs. P. H. Carpenter and R. Etheridge, Jun., 



would find its place without difficulty in the family of the 

 Haplocrinidfe, the special character of which is the presence 

 of a dome of oral plates. But we can find no family, either in 

 the Tessellate or in the Articulate division of the excellent 

 classification of Prof. Zittel*, to which we can refer the 

 larger specimens of Allagecrinus. We therefore propose to 

 institute for its reception the family Allagecrinida?, with a 

 definition essentially tlie same as that already given for the 

 genus. The inequality of size of the radials, owing to some 

 of them being axillary, is a character Avhich sharply distin- 

 guishes Allagecrinus from the Encrinida3, Apiocrinida3, and 

 Pentacrinidaj, and, in fact, from all the " Articulata," to which 

 division of the Miillerian classification it clearly belongs. It 

 is, however, one of the Palaeozoic Crinoids, and, like most 

 members of that group, retains several embryonic features. 

 Hence it adds one more to the many proofs which we have 

 already of the unsatisfactory nature of Miiller's definitions of 

 the Articulata and Tessellata. 



5. Locality and Horizon. 



Allagecrinus Austinii appears to be dispersed generally 

 throughout the shales and some of the limestones of the Scotch 

 Carboniferous system. We are acquainted with its distri- 

 bution in the east of Scotland much better than in the west. 

 The following may be taken as typical localities : — 



No. 16 Mine, Addiewell, near Bathgate, in the decomposed 

 No. 1 main, or Hurlet Limestone; Howood, near Johnston, 

 in shale above the Hurlet Limestone ; Catcraig Shore, near 

 Dunbar, and Burlage Quarry, near Dunbar, in shale above 

 the Skateraw Limestone ; Carlops Quarry, near Carlops, in 

 shale above the Carlops Limestone ; Koscobie, near Dunferm- 

 line, in shale above the limestone developed there. The 

 foregoing horizons are all in the Lower Carboniferous Lime- 

 stone group. 



6. On the Divisions of the Crinoidea. Articulata and Tessel- 

 lata ; Palceocriaoidea and Stomatocrinoidea ; Regularia 

 and Irregularia. 



Although Miiller's terms Articulata and Tessellata are 

 practically meaningless as regards the Crinoids, they have 

 nevertheless come to be looked upon as representing two very 

 distinct sections of the order, viz. the Mesozoic, Tertiary, and 

 Recent types on the one hand, and the Palaeozoic types on 

 the other. We think, however, that the time has come 



* Ilaudb. d. Palciontol. Bd. i. pp. o42-34u. 



