FIFTH REPORT OF THE DIRECTOR I908 20J 



droid graptolite and representing a genus near Thamnograptus or 

 Inocaulis. With that supposition, 'however, the transverse walls 

 and bifurcations of the branchlets would be difficult of explanation. 



We do not know of either an alga or an animal form of the 

 Coelenterata with which C o r e m a t o c 1 a d u s d e n s a could be 

 directly compared by its habitus. While there are many species 

 forming caespitose tufts among the Florideae, which order on ac- 

 count of the frequent development of strong cortical cells and the 

 transverse septation of the filaments would principally suggest it- 

 self for reference, none possess a structure the direct counterpart 

 of that of our species. There are, however, various forms in other 

 orders of marine algae which by their composition of a thick main 

 axis that bears a dense mass of bifurcating filamentous branchlets 

 invite comparison. As such a genus Penicillus among the Codiaceae 

 might be cited, in which an incrusted stipe bears a dense terminal 

 mass of frequently bifurcating filaments. 



Munier Chalmas had thought to have discovered this latter form 

 in thin ovoid or fusiform calcareous shells of the Tertiary described 

 as Ovulites which possess on their surface pores surrounded by fine 

 lines inclosing polygonal spaces, the whole forming a structure sug- 

 gesting somewhat of the main stipe of Corematocladus 

 d e n s a ; but as Solms-Laubach has pointed out, no such reticu- 

 lated design is seen on the surface of the calcified membrane of 

 Penicillus, although he recognizes Ovulites as a calcareous alga. 

 Our form may have been similar in the structure of the main stipe 

 to Ovulites although possessing instead of the calcification a thick 

 noncalcareous cortex. 



Horizon and locality. In the lower third of the Trenton lime- 

 stone at Glens Falls, N. Y. 



Mastigograptus ? flaccidus sp. nov. 



Plate 3, figure 6 



Associated with the described supposed marine algae in the 

 shaly intercalation of the Trenton at Glens Falls and by their 

 flaccid character and carbonaceous film, quite apparently belong- 

 ing to the same class with them, occur slender wormlike irregu- 

 larly bent carbonaceous bodies that are distinctly but the 

 macerated fragments of larger organisms. In one case the prox- 

 imal extremitv was observed which is well fitted to throw light 

 on the true nature of this form [see pi. 3, fig. 6]. This shows 

 a small attachment plate from which a slender main stipe arises that 

 monopodially gives ofY equally flaccid and slender branches. Both 

 the stipe and the branches exhibit at regular intervals circular to 



