GRAPTOLITES. 115 
In the punctate test and undulating axis, we have the characteristics of 
Retiolites, which, as illustrated by Geinitz, shows on one side the cell- 
partitions reaching to the well-defined axis. The same feature of Hetio- 
lites is shown im a still stronger degree in the figures of Edward 
Suess.* 
EXPLANATIONS OF Figures OF RETIOLITES ENSIFORMIS, Hall. 
Puate XIV. 
1, 2, 3. Individuals showing gradations in growth, and slight differences in their 
proportions. 
4, A nearly entire stipe of the largest size observed. 
5. An enlargement from the specimen fig. 4. 
Formation and Locality Quebec group ; near Point Lévis. 
Genus RETIOGRAPTUS,} Hall. 
Generic characters.—Frond simple ? or compound, consisting of numer- 
ous simple stipes in bilateral arrangement, proceeding from an axis or 
radicle, (or of single stipes growing from their own radicles ?) Stipes elon- 
gate-oval, or lanceolate, with longitudinal axis and reticulate structure; 
margins ornamented with mucronate points. The axis often extends beyond 
the substance of the stipe in a mucronate tip, and in one species there are 
long setze extending from what appears to be the base of the stipes. 
I had originally referred the Retcograptus tentaculatus to the genus 
Retiolites of Barrande (describing it under the genus Graptolithus). A 
farther examination of its structure, together with that of a species from 
the shales of Norman’s Kill near Albany, induced me to separate them from 
Retiolites, and propose the name of etiograptus. Subsequently an exam- 
ination of some specimens from the Utica formation from Lake St. John in 
Canada, revealed a minute compound form which is illustrated in fig. 9 of 
pl. xiv. Although presenting some slight differences from the other two 
known species, I conceive it not to be generically separable from them. 
The specimen is extremely interesting for its illustration of a mode of growth 
*Ueber Boémischen Graptolithen, von Edward Suess. Naturwissenschaftliche Abe 
handlungen, IV Band, IV Abth. Tab. VII, 1851. 
} A species of this genus has been describe din the third volume of the Palzon- 
tology of New-York, Supplement, p. 518; and in the Thirteenth Report on the State 
Cabinet of Natural History ; but no generic description was given. 
