334 REPORT—1 885. 
‘them in the Enromosrraca than in the MaLacosrraca, seeing they have 
not actually attained to the grade of the latter, but only approached to its 
larval development; whilst to the former the adult Nebalia has many 
very strong points of affinity. 
TI. Cerariocartp#.—Dr. Packard’s observations on the structure 
-of the Phyllopods, and his studies of the comparative anatomy of living 
and fossil forms, supply the paleontologist with sound reasoning in re- 
ferring the Phyllocarida to the Nebaliad type as a centre for a creat 
group of obscure fossil forms, and as a starting-point for the Decapoda. 
‘We have referred to his views in some detail in the foregoing pages. 
Order. Puytiocaripa, Packard. 
Genus Curatrocaris, M‘Coy. 
The generic characters of Ceratiocaris have been described by M‘Coy, 
‘Salter, H. Woodward, and Barrande in their several works and memoirs 
referred to in the sequel. James Hall, R. P. Whitfield, A. S. Packard, 
J.™M. Clarke, Fr. Schmidt, C. E. Beecher, O. Novak, and others have 
added much information, general and special, on this and allied genera. 
The appended synonymy of the genus supplies full references to published 
notices on Ceratiocaris and some of its allies. 
We offer the following diagnosis of Ceratiocaris. Carapace bivalved, 
probably with membranous attachment, no distinct hinge-joints being 
observable ; valves subovate, semiovate, subquadrate, or trapezoidal ; con- 
tracted in front with the end shar» or rounded above the median line 
of the valve; more or less truncate behind. Rostrum elliptical in shape, 
of a single lanceolate piece, chevron-marked. Antenne (?) obscure. 
Teeth often apparent. Body many-jointed, with fourteen or more seg- 
ments, of which 4-7 extend beyond the carapace, ornamented with deli- 
cate raised lines. Some or all of these segments bore small lamelliform 
branchial appendages.! Last segment, the longest, supporting three 
caudal spines, namely: (1), a strong tapering telson (style), thick at the 
top or proximal end, with its three-knobbed articulating surface (resem- 
bling that in the telson of Limulus), pointed at the other, and more or 
less spinose, as shown by the bases of little prickles; and (2), two 
shorter, simpler, lateral appendages (stylets), The surface of the valves 
has a lineate ornament, and the ventral margin has a thin raised rim. 
Respecting the abdominal appendages which Mr. R. Etheridge, jun., 
described in Appendix III. of the ‘Memoirs Geol. Survey Scotland : 
Explanation of Sheet 23,’ 1873, p. 93, he there remarks :—‘ A further 
advance in the structure of this genus of Crustacea has been satis- 
factorily established from specimens obtained at Lesmahagow by the 
Collector of the Geological Survey, viz. the presence of respiratory 
locomotive appendages. On a slab of thin-bedded shale are exposed the 
abdominal segments, telson, and caudal appendages of a Ceratiocaris. 
From the ventral margin of the terminal segment, to which are attached 
the telson-spines (Leptocheles, M‘Coy), proceeds a broad, paddle-shaped, 
membranous (?) expansion, presenting a strong marginal outline, 
with a transversely striated surface. This is followed by another similar 
appendage, proceeding in the same manner from the penultimate serment 
(somite). Along the dorsal margin there is seen what appears to be the 
1 See the ‘Sixth Report on Fossil Crustacea,’ Brit, Assoc. Report for 1872, p. 
323. ; 
e 
‘ 
