ON THE FOSSIL PHYLLOPODA OF THE PALHOZOIC ROCKS, 355 
Fig. 4 is a smaller and less perfect specimen. 
Fig. 5 some segments and appendages much like those of some spe- 
-cimens of C. stygia. 
Fig. 6 (C. acuminata) is an elegant carapace, ovately-trapeziform, 
slightly arched above, fully convex below, with a sloping, ogee, truncate 
posterior, and an acuminate front sloping rapidly down to the middle of the 
ventral margin, with its slope nearly parallel to that of the posterior trun- 
cation. It is finely striated longitudinally. This is very similar to some 
relatively narrow forms of C. stygia, particularly to Brit. Mus. ‘41898’ ; 
but still the details vary. It may also be compared with some forms of 
‘O. Murchisoni, such as M. P. G. x $ and x }, but not so satisfactorily. 
Fig. 7 is a crushed portion of a large carapace, delicately striate on the 
ventral region, and four (?) crushed abdominal segments. Probably of the 
‘same species as fig. 6, as intimated by Prof. Hall (p. 417*). 
28. CERATIOCARIS ACULEATA, J. Hall. 
1859. C. aculeatus, J. Hall. ‘Geol. Surv. N. Y. Pal.’ vol. iii. Part I. p. 422*; Part IT. 
(plates), 1861, pl. 80 A, fig. 10. 
This is apparently an ultimate segment (split),a broad telson (split ?), 
cand one stylet. If so, the telson is 20 mm. long, and 5 mm. broad near its 
base, and is comparable with C. robusta. Itis fromthe Waterlime Group, 
-at Waterville, N. Y. 
29. Crratiocarts Nerina, Fr. Schmidt. 
1883. Ceratiocaris Notlingi, Fr. Schmidt. ‘Mém. Imp. Acad. Sci. St.-Pétersbourg,’ 
ser. 7, vol. xxxi. p. 84, woodcut fig. 5; pl. 6, figs. 8, 9; pl. 7, fig. 12. 
This has an elegant carapace (about 72 x 38 mm.), comparable with 
some individuals of our C. Murchisoni (Salter’s ‘leptodactylus’), but not 
‘quite agreeing in all details. It is nearly semi-ovate in lateral outline, 
sharp in front, truncate with neat hollow curve behind. It closely ap- 
proaches Dr. James Hall’s CO. acwminatus, which, however, is fuller in 
the ventral margin. The surface is delicately striated longitudinally, 
‘concentric with the ventral border ; it is bordered ventrally with a thin 
raised rim. 
A fine set of caudal spines (pl. 6, fig. 8) shows a telson (style) 38 mm. 
llong, 11 mm. broad at its base, tapering rather rapidly, and ridged. The 
main ribs are tuberculate, and a blunt spine stands out on each side 
below the triangular bulb or base of the telson. One stylet (22 mm.) is 
rather broad, ensiform, and flat, except a faint median ridge. Fig. 9 is 
‘an imperfect style. 
From an Upper-Silurian limestone, near Rootzikiill, Oesel, in the 
Baltic. 
30. M. Barranpe’s Species or CERATIOCARIS. 
The following Ceratiocarides have been carefully described and figured 
‘by the late M. J. Barrande; and we proceed to point out their most 
notable features, indicating characters by which they can be compared 
with the British and other forms. 
(2.) Cerratiocaris pocreNs, Barrande. 
1856. Leptonotus Bohemicus, Barr. ‘Parall. entre la Bohéme et la Scandinavie,’ p. 58. 
1865. Hurypterus, sp. Barr. ‘Défense des Colonies,’ vol. iii. p. 235. 
AA2 
