1 7 8 



NEW YORK STATE MUSEUM 



tinctly projecting, inclined at 15 , and furnished with short apertural mucros. 



Their apertural margins slightly concave. They number about 14 in the 



space of 10 mm. Sicula and stem not observed. 



Position and locality. A single specimen observed in the Xormanskill 



shale at Glenmont near Albany, on one of the slabs that are covered with 



a dense mass of Dicellograptus g u r 1 e y i . 



Remarks. In its habit this species bears closer resemblance to Call o - 



graptus elegans Hall, than to any other species we know; and 



inasmuch as that species is the genotype 

 of Callograptus, a reference of our species 

 to Callograptus will suggest itself at first 

 sight. We have preferred to place it with 

 Desmograptus for two reasons ; first, the 

 strong development of the undulations and 

 reunions of the branches and second, the 

 prominence of the thecae. The first char- 

 acter is just indicated in Callograptus 

 e 1 e o- a n s ; one could therefore assume 

 that it had been further developed in D. 



s *%* 4 '%°i:^^^o?^±:y^ t e n u i r am o su s, especially since in the 



specimen showing form of branches. Fig. 85 En- 1 .... 



Urgementof oti.erportion showing form of thecae. xs latter also dissepiments are observed be- 

 tween the branches when these fail to approach sufficiently. In this regard 

 our species would hence seem to hold a position between the genera Callo- 

 graptus and Desmograptus, similarly as other forms seem to connect Callo- 

 graptus and Dictyonema. The thecae however, exhibit a form hitherto not 

 observed in species of Callograptus; they remind one of those of Dendro- 

 graptus s. sir. and Dictyonema. But also in regard to the? thecal form, 

 there seem to exist within the confines of Desmograptus and Callograptus 

 divergencies such as were found in Dendrograptus (here separated into 

 Dendrograptus s. sir. and Mastigograptus by this criterion). 



