FIFTH REPORT OF THE DIRECTOR I908 



197 



the genera Climacograptus, Cryptograptus etc. On account of the 

 great interest which this graptolite occurrence has in regard to a 

 possible correlation by intercalation of the corresponding graptolite 

 horizon with the limestone series of the Trenton, this faunule will 

 be studied separately after more extensive collecting. 



The fact of the occurrence of graptolites proper together with the 

 supposed marine algae may seem suggestive of the graptolite nature 

 of all the fossils, especially if it is taken in account that some of 

 the algoid forms exhibit in the carbonaceous films they have 

 ieit, the distinctness and sharpness of graptolite remains in spite 

 of their subdivision into hair-fine branches. On the other hand it 

 could be urged that from the well recognized evidence of the 

 growth of many graptolites on seaweeds the concurrence of the 

 two in the same bed is a logical corollary. But, if the surrounding 

 conditions at Glens Falls are taken into account, it becomes evident 

 that the graptolites and the algoid fossils belong to different marine 

 life zones. The very irregular surface of the thin bedded limestone 

 and the patchy distribution of the black shale in depressions of 

 the limestone, indicate that the deposition took place in rather turbu- 

 lent water. The comminuted condition of the true graptolites 

 shows that they drifted in from the open sea, while the fine preser- 

 vation of the much more delicate algalike remains indicates that 

 they grew where they are found and were sessile forms of the 

 Lttoral zone. 



Dr Ilovey has had the kindness to send me the types of two of 

 the species of marine algae described by Professor Whitfield, for 

 comparison and study. The structural details of these — presently 

 to be described — leave no doubt of their vegetable origin. One 

 is a distinct coralline alga from the Trenton of Middleville, N. Y. 

 [see pi. t, fig. 1] , the other (Callithamnopsis fruticosa) 

 a seaweed from the Trenton of Platteville, Wis. The latter 

 is so closely related to one of the Glens Falls forms (C . d e 1 i c a - 

 tula) that by inference the latter must also be an alga although 

 its structural features are not as distinctly seen. We will for this 

 reason first note these two longer known species of manifest algal 

 character and then attempt to demonstrate the vegetable nature 

 of the Glens Falls forms by reference to them. 



Primicorallina Whitfield 



This genus of calcareous algae was erected for a single species, 

 P. trcntonensis Whitfield, from the Trenton limestone of 

 Middleville. The form is described by its author as follows: " (The 



