GRAPTOI.ITES OF NEW YORK. PART 2 233 



The most striking feature of at least two of the species of Corynoides 

 observed in our rocks are the apertural appendages which, resembling 

 symbolized flames, cap the bundle of thecae. They consist of several pairs 

 of diverging curved spines (presumably one pair for each theca) which 

 project from tonguelike processes of the thecae. 



In case it should be proven that the rhabdosome indeed formed com- 

 pound colonies, the latter would be synrhabdosomes, such as the colonies 

 of Diplograptus are, where each component rhabdosome begins to grow 

 from its own sicula ; and not comparable to the branching colonies of the 

 Dichograptidae. Corynoides could then appear to be an aberrant type of 

 the Axonophora. There is, however, no trace of an axis or virgula in either 

 the sicula or the outgrowing branches seen nor would there seem to be any 

 need for a strengthening rod in the short compact rhabdosome. 



If, on the other hand, the rhabdosome represent the whole colon)', if 

 there is no axis and the thecae bud in single series and succession, this form 

 could be compared to Azygograptus and considered as a peculiar late 

 development of the Didymograpti. Such view would, however, be contra- 

 dicted by the peculiar character of the thecae and especially that of the 

 apertural appendages which seem to suggest a more complex structure of 

 the thecae than is found in the Dichograptidae. We consider it, for this 

 reason, possible that the genus may be found to represent an aberrant 

 branch of the Dendroidea and leave it, for the present, among the formae 

 incertae sedis. 



Whatever the derivation of this remarkable group of minute forms 

 ma) - have been, it stands so distinctly apart in the shape and structure in 

 which it presents itself to us, that we fully agree with Hopkinson and 

 Lapworth in separating it from the rest of the Graptoloidea and placing 

 it in a separate family, which since the name Corynograptus has again 

 been abandoned, would have to receive the name Corynoideae instead of 

 Corynograptidae. 



Our rocks have furnished five forms, all of which are easily distin- 

 guished by the relative width and length of their rhabdosomes. Since 



