279 
Tliillipsia J3rO)ipnku’li, 11. Bronn, 1848, Index Pa]., p. 958. 
,, ,, J. Morris, 1854, Cat. Brit. Foss., 2ikI eel., p. 114. 
Grijfif hides Idrongniartil, E. cVEiclnvald, 18G0, Letlia>a Eossicn, I, p. 1437, pi. 54, fig. 8 
(non Fischer cle AYaldheiin). 
,, ohsoleius, Idem, 1860, ihid., p. 1410. 
Idhillipsia Tdichwcddl, V. v. Moeller, 1867, Bull. Soc. Imp. Nat. Moscou, p. 187. 
The cephalic sliield is sub-semicircular, convex, and its genal angles 
are very little prolonged, not extending beyond the first articulation of the 
thorax. The glabella is rather thick and ventricose, making a slight projection 
on the rudimentary border of the frontal margin. The thorax is composed of 
eight segments ; its axis possesses the same breadth as the lateral lobes ; all 
three are convex. The pygidium, about one-third broader than long, is semi- 
elliptical, and is furnished with a rather wide limb, to which there is a 
corresponding internal doublure of the same width ; its axis is composed of 
ten segments, the whole of which form an isosceles triangle, the angle at the 
apex being very acute, but truncated ; the rings arc simple, the ipiper one is 
three millimetres broad, and the .loAVcr only one millimetre ; the lateral rings, 
eight in number, are divided into two lengtlrways, by a small groove, much 
less pronounced than the grooves separating the rings, and only just perceptible 
to the naked eye. The whole surface is covered with fine granulations, not 
always easy to see when the specimens have lost their first freshness, as these 
Australian specimens have. 
Dimensions. —A. nearly perfect specimen is twenty-five millimetres 
long, of wdiich length the cephalic shield occupies seven, and the pygidium 
eight, its breadth is fourteen millimetres. 
Deliitions and Differences. — According to Moller, who has published 
a general review of the Carboniferous Trilobites, accompanied by some good 
observations on certain errors that I shall have an opportunity of treating later 
on, several authors have confounded G. Eichwaldi with species most unlike 
it. Thus, the llussian Palasontologist to whom it is dedicated, has designated 
under this name the species wdiioh McCoy has described under the name G. 
nmcronotits, and which is easily distinguished from it by its caudal appendage. 
Yerneuil and Morris have made the same mistake. I myself have thought 
with G. Tischer de M^aldheim, and some other authors, that G. Brongniarti 
of the Russian Pala:ontologist was distinct from G. Eichwaldi, of wliich 
