8 



KEFOliT — 1884. 



of a Goniatite, from the Goniatiteu-Kalk of Altenau, in the Hartz. In 

 general appearance the figure ajDproaches Pholadocaris. 



Synoptical Plan op the Discinocapjda. 



Shield without a median 

 dorsal suture. 

 (Type, Discinocaris.') 



1. Posterior margin") 

 entire and rounded. 

 i. Cephalic notch | 

 ( = nuchal suture) j- 

 angular 



1. Shield not. ridged | 



nor furrowed J 



2. Shield having ^ 



radiate furrows and .- 



ridges . . . ) 



ii. Cephalic notch ) 



rounded. . . I 



2. Posterior margin"] 

 angular ; shield | 

 with radiate ridges, j. 

 Cephalic notch [ 

 rounded . . ) 



S. Posterior margin in- \ 

 dented ; cephalic 

 notch angular . ) 



A. Posterior marginal 

 deeply notched ; 

 cephalic notch, 

 angular . . . )■ 

 A. Concentrically 

 striate, like Disci- \ 

 nocaris, &c. . .J 

 b. Not concentrically 

 striate. 



1. Test with radiate 



ornament 



2. Test smooth ; mi- 



nute 



notch broad 



i. DISCINOCARIS 



notch narrow 

 ii. Spathiocabis 



iii. Piioi.Ai>oc.Yi:is 

 iv. Elijpsocabis 



V. LlSGOCARIS 



vi. Cakdiocakis . 

 vii. DirTEnocARis 



Shape or outline of Shield 

 Species, (complete, and measured 



outside the notches). 

 Brmrniana, duhia, lata circular. 



triasica 



s|i. now 



congener • . 

 Emersonii 



V small form 



ungulina . 



Leeii . • • 

 sp. nov. 



Dewalquei . . 

 sp. nov. . . 



Lutltcri m • 



Itnemeri, hipariita 

 Veneris, Koeneni 



pes-cervm, vetusta 

 procne . • 

 permm-dsedali . 

 Etheridgei . 



oval. 



obovate. 



oblong. 



oblong. 



obovate. 



oval. 



cuneiform, 

 obovate. 



oval, 

 suboblong. 



subpentagonal. 



narrow obovate. 

 broad obovate. 



obovate. 



subquadrate. 



suboblong. 



oval. 



viii. Pterocaris 

 ix. Crescentilla 



bohemicu 

 pugnax 



obovate. 

 oblate. 



As in all other natural groups, it is difficult or impossible to arrive 

 at a perfectly linear arrangement ; the order, therefore, in this plan of 

 the Discinocarids does not quite correspond with that in the foregoing 

 list of genera and species, which is followed in the descriptions. 



I. Discinocaris, H. Woodwai-cl, 18G6. 'Quart. Journ. Geol. Soc' vol. 

 xxii. p. 503 ; and ' Geol. Mag.' vol. iii. 1866, p. 72. 



This Pliyllopod has a round, oval, ovate, or oblong shield, slightly 

 •conical, without a median suture, but crossed anteriorly by an angular 

 nuchal suture, often leaving a corresjjonding notch. Concentrically 

 striate, like its congeners. 



1. Discinocaris Broivniana, H. Woodward, 1866. ' Quart. Journ. Geol. 

 Soc' vol. xxii, p. 504, pi. 25, figs. 4 and 7, andf. 5 side view, &c. ' Geol. 

 Mag.' vol. iii. 1866, p. 72. 'Catal. W.-Scot. Fossils,' 1876, p. 7. 'Catal. 

 Cambr. and Silur. Foss. Pract. Geol. Museum,' 1878, p. 28. ' Proceed. 

 Belfast Nat. Field-Club,' 1877, Appendix, p. 122, &c, pi. 7, f. 25 a and 

 25 c. 



This is a circular shield, 15 mm. in diameter. Slope of nuchal 

 euture, 60° ; diameter of disk-shaped carapace, 7 lines ; width of nuchal 



