148 Pi'of. 0. Novak — On a Dhcinocaris from Bohemia. 



11. — On the Occurrence of a New Form of Discixocaris in the 

 Graptolitio Beds of the " Colonie Haidinger " in Bohemia. 

 By Professor Ottamar Novak. 



IN the Quart. Journ. Geol. Soc, vol. xxxvi. 1880, p. 617, Mr. 

 John E. Marr mentions having examined three specimens 

 of a Phyllopodiform Crustacean discovered by Mr. Martin Dusl in 

 the strata of "Colonie Haidinger," situated not far from the village 

 of Gross-chuchle, south of Prague. 



The specimens were then identified with Discinncnris Broicniana, 

 H. Woodw., figured and described in the same Journal, vol. xxii. 

 1866, p. 503, pi. 25, figs. 4, 5. and 7. They are also mentioned 

 by Dr. H. Woodward and Prof T. Rupert Jones in the Third Report 

 of the Committee on the Fossil Phyllopoda of the Palaeozoic Rocks, 

 1885, p. 2, under Mr. Marr's specific determination. 



Having worked for some time past on a revision of the fossil 

 Phyllojwda occurring in the Palaeozoic rocks of Bohemia, I examined 

 the three specimens in Mr. Dusl's collection, besides two others 

 collected by myself in the same beds some years ago. 



The following figure and description give sufficient evidence of 

 the characters of the fossil in question. 



Biscinocaris Dusliana, Novak. Nat. size. 

 In the Geological Museum of the Bohemian University at Prague. 



Description. — The shield flattened, oval in outline, without any 

 median suture, but truncated in front by a nuchal notch, leaving a 

 broad re-entrant angle, with rather concave sides and with an apex 

 reaching about one-third of the shield's original length. Width of 

 the nuchal notch precisely one-sixth of the entire circumference. 

 Surface finely striated ; the strife disposed excentrically round about 

 the apex of the frontal notch. The triangular frontal piece wanting 

 in all five specimens under examination. The shield, if complete, 

 would be about 22 mm. long, 19 mm. broad. The total length from 

 the apex of the notch to the posterior margin being 15 mm. ; slope 

 of nuchal suture about 45°. 



The superficies of the shield seems to have been originally some- 

 what convex, but appears to have been flattened by forcible 

 compression, as indicated by the radiate fissures in our Woodcut. 



It is evident that the carapace just described represents a new 

 form of Discinocaris, for which I propose the specific appellation of 

 D. Dusliana, after Mr. Dusl, who first drew attention to the fossil. 



Discinocaris Broicniana, H. Woodw., differs from the Bohemian 



