THE 



GEOLOGICAL MAGAZINE. 



NEW SERIES. DECADE III. VOL. II. 



No. IX.— SEPTEMBER, 1885. 



OIRXO-XJSTJ^IL, JV^I^TIOXjIES. 



I. — Notes on the British Species of Cebatiocarts. 

 By Prof. T. Eupert Jones, F.E.S., and Henry Woodward, LL.D., F.R.S. 

 (PLATE X.) 

 ^E. PACKAED'S observations on the structure of the Phyllo- 

 poda, and Ms comparative anatomical studies of allied living 

 and extinct genera, supply the palseontologist with sound reasoning 

 for referring the Phyllocarida to the Nebaliad type as a centre for 

 a great group of obscure fossil forms, and as a starting-point for 

 the Decapoda.^ His vievs^s have been referred to in some detail in 

 the Geol. Mag. for August last, pages 349-352. 



Order Phyllocarida, Packard (1879). 

 Genus Ceratiocaris, M'Coy (1849). 



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, E. P. Whitfield, 

 A. S. Packard, J. M. Clarke, Fr. Schmidt, C. E. Beecher, 0. 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 kindred. 



We offer the following diagnosis of Ceratiocaris. 



Carapace bivalved, probably with, membranous attachment, no 

 distinct hinge-joint observable ; valves subovate, semiovate, sub- 

 quadrate, or trapezoidal ; contracted in front with the end sharp or 

 rounded above the median line of the valve; more or less truncate 

 behind. Eostrum elliptical in shape, of a single, lanceolate piece, 

 chevron-marked. Antenna (?) obscure. Dentate mandibles often 

 apparent. Body many-jointed, with fourteen or more segments, of 

 which 4-7 extend beyond the carapace ; ornamented with delicate 

 raised lines. Some or all of these segments bore small, lamelli- 

 form, branchial appendages.^ Last segment longest, supporting 

 three caudal spines, namely, (1) a strong tapering telson (style), 

 thick at the top or proximal end, with, its trifid articulating surface 



1 See "Monograph of the Phyllopod Crustacea of Worth America, with remarks 

 on the Order Phyllocarida. By Lr. A. S. Packard, jun. (Extracted from the 

 Twelfth Annual Report of the U. S. Geol. and Geograph. Survey), 1883." 



2 See the Sixth Report on Fossil Crustacea, Brit. Assoc. Report for 1872, p. 323 ; 

 and Geol. Mag. Vol. IX. p. 564 ; also a descriptive note by Mr. R. Etlieridge, jun., 

 in the Mem. Geol. Surv. Scotl., Explan. Sheet 23, 1873, p. 93, and Ann. Mag. 

 Nat. Hist. ser. 4, vol. xiv. 1874, p. 9. 



DECADE III. VOL. II. — NO. IX. 25 



