lxxi1v DESCRIPTIVE REMARKS. 
a Carboniferous Limestone species frequent in Ireland. The group 
of Trilobites entirely disappear at the close of the Carboniferous 
period. Many Crustacea of other orders make up for the small num- 
ber of Trilobites. Limuloid forms of the Order Pecilopoda are re- 
presented by the Belinurus trilobitoides, fig. 7, from the Coal Mea- 
sures of Coalbrook Dale, and B. Regine from Coal shale, Queen’s 
County, and county Clare; they differ from the modern Limulus in 
the moveable condition of the body segments. Of the Phyllopoda, 
Leaia Leidyt, has been described from the Coal strata of Ardwick ; 
and small forms of Ostracoda, Leperditia subrecta, fig. 4, a-c, are 
abundant in the Lower Limestone shale of Ireland, and a larger genus 
Entomoconchus Scoulert, fig. 5, a, 6, in the Irish Carboniferous Lime- 
stone. ‘To the Macrurous Crustacea it is believed that Paleocrangon 
from Carboniferous strata, Fifeshire, and Pal@ocarabus dubius from the 
Coal strata of Shropshire, belong. 
Fisn remains are abundant in Carboniferous strata—placoid fishes 
being at their maximum development. In the order Plagiostoma the 
defence spines, or Ichthyodorulites, are included, such as the Silurian 
Onchus, Pl. xxvu,, figs. 7, and 8, and Oracanthus of the Carboniferous 
Limestone, *Zristychius, Pl. 41, fig. 8, Carboniferous shale, and Gyra- 
canthus of the Coal Measures. 
The family Cestraciontide, of which the Port Jackson Shark (Ces- 
tracion) is a living example, includes numerous palatal and other teeth 
found in the Carboniferous Limestone of Farlow, Shropshire, Bristol, 
and Armagh ; Psammodus porosus, Pl. 41, fig. 9, a, 6, is one of the 
largest and most abundant of these peculiar crushing teeth, in the 
Bristol and Armagh Limestone; Orodus ramosus, fig. 10, is another 
large tooth of a different form ocurring in the Lower Limestone; 
Helodus gibberulus, fig. 41, a smaller tooth of variable shape, is frequent 
in the Armagh limestone. Pecilodus Jones?, fig. 12, is a peculiar form 
of tooth also found in the Armagh limestone; and Petalodus Has- 
tingsi@ occurs in Yorkshire and in the Carboniferous Limestone shale 
at various localities in the north of Ireland. Large Sauroid fishes are 
prevalent in the Coal Measure strata of Scotland and Ireland. In the 
Lepidoganoid, named by Agassiz LHoloptychius Hibberti, but which 
Professor Owen has placed in the genus Rhizodus, fig. 14, the jaws are 
armed with formidable teeth The fish Pal@oniscus Robisoni, fig. 15, 
a, b, also from the Coal Measures of Burdie House, Edinburgh, be- 
longs to the same group of Lepidoganoids, a family which increases in 
number during the Carboniferous epoch. The genera, Amblypterus and 
Celacanthus, also Coal Measure fish, continuing with it into the Per- 
mian strata. 
The Lasyrryrnopont type of Reprires (Amphibians) are abund- 
antly represented in Upper Carboniferous strata. -Apateon and Arche- 
gosaurus, Sauro-Batrachian, or Salamandroid reptiles, found in Coal 
Measure strata in Germany; and Dendrerpeton, described by Principal 
Dawson, from the Coal field of Nova Scotia, belong to the order 
Ganocephala, The order Labyrinthodontia include Baphetes, from 
