there are only about 1 1 radial ribs, which fact justifies the name proposed by 



ROEMER. 



On the other hand, there are examples of larger specimens of the type 

 species ever described or illustrated. There are many of them among the 

 specimens of Hall which in point of size are comparable with the variety 

 pictured by Scupin. The same will hold good for the illustration of the 

 species in Tschernvschew's work. With regard to this point Clarke's 

 measurements of the two forms are worthy of mention, for in them the size 

 relation is entirely the reverse. According to him the type species is 28 mm. 

 long and 35 mm. wide, while the variety (or his species) measures 20 mm. by 

 25 mm. , 



Locality : — Between Mien-tien and Shang-shui-tang, Nan-ning-hsien, 

 Fan-ning-fu, prov. Kwang-hsi. Also at Mien-tien. Found in association with 

 AtJiyris conccntrica Dalnianclla striatiila. ■ .;t . 



Geological Age : — Germany tiiis is found in the Iberg Limestone, 

 which is the lower division of the Up|)er Devonian. , la America Spirifcr 

 ziczac is recorded from the Plamilton Group, or ihc upper division of the 

 Middl • Devonian. The Chinese , fossil seems to represent the Middle 

 Devonian Age as in,, America, for it is found, in , association wi'h Atliyris 

 .conccntrica. :■, 



Atrypidae. ' ' ' ■■ - : 



Atrypa, Dalman. 

 A Iry a reticularis Linne, var. richthofeni Kayser em. Fri:ch. 

 '''' ■ PI. XXIL, Figs. II and 16; PI. XXIIL, Fig. 7. 



1883. r/<r//^'Z;c/(r«/, Kayser : —Von Richthoeen's China, vol. IV., 



p. 92, pi. XIIL, fig. 2. 

 191 1. Atrypa reticularis var. ricJithofcni, Frech : — Ditto, vol. V.,. p. 33. 



Von RiCH iHOFEN collected .this species at Lung-tung-pei ;in the eastern 

 poriion of the province of Sze-chuan together with OrtJi^is Mac Farlaiici d^nd 



