Vdl 1. Sun— Cambrian Faunas of Uorlk China (iv) 21 



Surface marked by two stages of growth lines. The young stage is chnrncterized 

 by its undulating growth-lines, while the adult stage is marked by ordinary growth-lines 

 crossed by very fine radiating striae. A triangular median depression is slightly marked, 

 and outlined by two slightly elevated broad and low ridges which are only seen on the 

 perfect specimen of the shell. 



This species resembles Lingulella kayseri Grabau in form, but differs in the char- 

 acter of the growth-lines, in the more obtuse beak and also in size. 



This species is characterized by two different stages of growth lines, subrectan- 

 gulnr form, and the obtuse angle of the beak of the shell. 



1 2 



Measurements: — Luanchou Yehli 



Length 12.00 18.5 



Width 10.50 12.8 



HoKizoN .\ND Localities: — Upper Cambrian: from thin-bedded clayey limestone 

 of Luan-chou. Collected by Dr. F. F. Mathieu. Also in lower part of Fengshan forma- 

 tion near Yeh-li. Coll. by Y. C Sun. 



Lingulella liui Sun (sp. nov.) 



Plate I, Figs. 9a-9c. 



Shell small, elongate egg-shaped with both posterior and anterior end obtusely 

 rounded: depressed-convex, the frontal margin obtusely rounded; width gradually 

 increases from the frontal margin to the middle of the shell. Beak obtuse with an angle 

 of 110° ; greatest width is in the middle of the shell. 



The outer surface usually has a glistening appearance and is marked by n^gular 

 fine but sharp concentric strite and coarser lines of growth at frequent intervals. Wlien 

 the outer shell is exfoliated, it is distinctly marked by many elongated pustules, and the 

 frontal margin by very fine radiating strife. 



This species is represented by three specimens all apparently ventral valves. It 

 presents quite distinct a form from any known Chinese species. 



This species resembles LingvMla ferruginea Salter in general appearance, but 

 differs in the character of the shell, in the more elongated form, and in the absence of 

 the distinct radiating striie. Three specimen measure respectively ; length 5.5 mm. 4.0, 

 5.5, width 3.5, 3.3, 8.4. 



