Genus Megalograptus. 348 



Genus Megabgraptus — (S. A. Miller). 



\_Etym. — Gr. megale, great ; graptos, writing ; in allusion to the 

 remarkably large size of the polyp.] 



Generic characters. — Body large, cylindrical, or subcylindrical, 

 covered with polyp cells, and bearing fronds with spinous processes. 



In the absence of more than detached pieces of the typical species, 



Megalograptus Welclii, reference to its characters are necessary to a 

 very clear comprehension of the genus. 



Megalograptxis Wehhi — (S. A. Miller). 





m 





ITI (Tl 





>?i© e> 5'^<r>'^<rv.<^^<^ *,o -^o"^ 



'^-,t^<^i'\ 



i») 





Fig. Z5— Megalograptus Welchi. Cylindrical part of the body showing polyp cells. 



Body large, cylindrical, or subcylindrical and covered, like all other 

 graptolites found in the Cincinnati Group, with a jet black film of car- 

 bonaceous matter, which readily burns in a flame. Over the outer 

 surface there are numerous irregularly distributed circles of the film, 

 which I regard as the compressed cells of the polyp. Fig. 35 repre- 

 sents a specimen, three inches in diameter, and a little over two inches 

 in length. It has been compressed to about one half an inch in thick- 

 ness, but the compression has not so destroyed the edges, as to prevent 

 the tracing of the entire circumference. The cells, as shown in the 

 figure, though not any too numerous, yet, on account of the white 



