—<=<a ss 
Revision of Bryozoan Genera.—Cumings. 207 
ing generations till they came to be present even in the axiat 
region. Their function, if they had any, must have been con- 
nected with the surface of the zoarium. Their presence in the 
axial region is interesting only as it suggests ancestral char- 
acters. As more acanthopores are added, they are added in 
the mature region. Hence the two sets co-exist in this part of 
the colony. 
This peculiarity of the acanthopores is by no means con- 
fined to the Heterotrypide, but may be seen in Batostema, 
“Amplexopora, Hemiphragma &c. 
We come now to a consideration of the type species of 
the genus Heterotrypa Nicholson, namely Monticulipora (He- 
terotrypa) mammalata Nich. (=Heterotrypa frondosa Ul- 
rich.)* 
Dekayia perfrondosa nom. noy. (Pl. IX, figs. 9, 11-13, 15, 
oe ee a, es. 1; 6: PE’ XI, fe: 6; Pi. AIL fig. -2) 
as I shall call this form, for reasons presently to be 
discussed, is the common Cincinnati species first ad- 
equately described by Nicholson under the name Monti- 
culipora mammulata, and identified by him’ with the 
form figured and described by Edwards and Haime+ 
as the Monticulipora mgmmulata D’Orbigny. I fully agree 
with Mr. Ulrich that this is not the Chaetetes mammu- 
latus of Edwards and Haime. It is also in my _ opin- 
ion not the Chaetetes frondosus of Edwards and Haime. 
There are, however, in my possession four specimens of a 
form that agrees so closely with both the figures and descrip- 
tion of Chaetetes frondosus E. & H. that I am forced to re- 
gard them as identical species. This form is Homotrypa fron- 
dosa (E. & H.) described herewith. 
* Chactetes mammulatus (non D’orbigny) NicHOLSON Quar. Jour. Geol. 
ace. Lond., 1874, vol. xxx, p. 508, pl. xxx, figs. 2, 2b;—Pal. Ohio., ii, 1875, p. 
207. 
Monticulipora (Heteotrypa) mammulata (non D'Orbigny) NICHOLSON, 
Pal. Tab. Corals, 1879, p. 294, pl. xiii, figs. 1-1b; Genus Monticulipora, 1881, 
p. 104, pl. vi, figs. 1-1g.—JAMES AND JAMES, Jour. Cin. Soc. Nat. Hist., xi, 1888, 
p. 16.—]. F. James, Ibid, vol. xviii, p. 69. 
Chetetes frondosus Quenstedt. Roehren und Sterncorallen, 1881, p. 74, 
pl. exlvi fig. 8. : 
Chetetes frondosus limatus QUENSTEDT, Ibid, p.74, pl. exlvi, fig. 9. 
Heterotrypa frondosa Uric, Jour. Cin. Soc. Nat. Hist., vol. vi, 1883, 
3 
Monticulipora frondosa Wuite, Eleventh Ann. Rep. Geol. & Nat, Hist. In- 
diana, 1882, p. 380. pl. xl viii, figs. 2, 3. ‘ 
Not Chetetes frondosus D’ORBIGNY 1850, and EpWarkDs AND HAIME 1551. 
+ Pol. Foss. Terr. Pal., 1851, p. 267, pl. xix, fig. 1. 
