DISCUSSION OF THE CAMBRIAN FAUNA. 47 



DISCUSSION OF THE CAMBRIAN FAUNA OF CHINA. 



The discussion of the fauna might be extended to include a detailed 

 comparison of each species with forms resembling it from Cambrian forma- 

 tions in other parts of the world, but the illustrations on the plates show the 

 characters of the species so well that I will leave to each investigator the 

 decision as to whether the species of the fauna he may be considering are 

 similar to those of the Chinese Cambrian. In the following notes only general 

 statements and conclusions are given. 



Algce. So far as known no true Algae have been found, but fillings of 

 mud cracks and annelid trails occur resembling stems of Algae ; their true char- 

 acter may be determined by comparison with similar recent phenomena. 



Foraminifcra. The almost total absence of Foraminifera is probably 

 due to oversight connected with hurried collecting and to the absence of 

 favorable conditions for the presence and preservation of specimens. The 

 one species Globigerina ? mantoensis [plate i , fig. i] is all that has been detected 

 in the relatively large collections. 



Porifera. Only a few spicules of Protospongia are known. These indi- 

 cate that when a favorable locality is discovered a fine representation of the 

 sponges will be found. 



Anthozoa. One genus with one species of Coscinocyathus suggests the 

 great development of the Archseocyathinse in the Atlantic Basin fauna as 

 found in the islands of Sardinia and Newfoundland, and the Pacific Basin 

 fauna in the Cordilleran area of Nevada in western America. In Asia the 

 type is known from Siberia as described by Eduard von Toll [1899]. 



Annelida. A few trails are all the traces that have been found of the 

 annelids. One of these is illustrated by plate i, figure 5. 



Bracluopoda. Among the brachiopods none of the genera is peculiar to 

 the Chinese Cambrian. All belong to genera found in the Middle Cambrian 

 of western North America and northwestern Europe. The genus Micromitra 

 is well developed and I have inserted on plate i, figure 13, a photographic 

 reproduction of a specimen from the Middle Cambrian of British Columbia, 

 that has the pedicle and surface spines finely preserved. 



Gastropoda. The patelloid forms are represented by two genera, 

 Scenella and Matherella, and three species, two from the Middle Cambrian 

 (018,070) and one from the Upper Cambrian (056); the cone-shaped forms 

 by three species of the genus Plckionclla, one of which, Hdcionella rugosa 

 chinensis [plate 5, fig. 8], has a dissepiment toward the apex, a feature also 

 shown by both H. ? ? simplex [plate 5, fig. 1 1] and H . ? clurius [plate 5, fig. 7]. 

 The coiled gastropods are of unusual interest, as three forms, Matherella? sp. 

 undt. (055) [plate 5, fig. 6], Pelagiella chronns (01. 04, 018) [plate 5, figs. 9, 

 qa-b], and P. willisi (072) [plate 5, figs. 12, 13] are from the Middle Cambrian. 



Pteropoda. The species of the genera Ilyolithes and Orthotheca are of 

 the usual Cambrian type. I have introduced on plate 6, figure 8, a reproduc- 



