7 
Revision of ‘Bryosoan Genera.—Cwumings. 209 
As compared with any specimen of Dekayia perfrondosa 
that has come to my notice, Homotrypa frondosa is much 
closer to Edwards and Haime’s species. The former has from 
12 to 16 monticules to the square centimeter. The monticules 
are from I—2 mm. in diameter and are either inconspicuous, 
in which case they may be rounded; or sharply elevated and of 
small diameter. They almost always bear cells smaller than 
the average. Wherever I have seen a stellate monticule in 
D. perfrondosa, the appearance has always been due to strings 
of small cells on the flanks of the monticule. 
Homotrypa frondosa comes from the very top of the Lor- 
raine* or base of the so-called Richmond formation; and of 
course the same objection can be brought against it that was 
urged by Mr. Ulrich against considering H. dawsoni (a nearly 
related form) as possibly Edwards and Haime’s species, name- 
ly that it probably does not occur at Cincinnati. This objec- 
tion is scarcely valid, since Edwards and Haime state that 
Chaetetes frondosus occurs at both Cincinnati and Oxford, 
Ohio; a statement that could very well be true of the present 
form. As to the identity of the species figured by Edwards and 
Haime, and D’Orbigny’s types, I believe with Mr. Ulrich that 
the former gentlemen had D’Orbigny’s specimens before them, 
for they practically say as much in accrediting the species to the 
collection of the latter. In the preface to their work they also 
acknowledge their indebtedness to D’Orbigny and others for 
assistance and the loan of specimens. I do not believe, how- 
ever, that the form figured by Edwards and Haime is the same 
as that from which D’Orbigny drew up his one line description 
“Espéce a larges frondes dont les monticules sont coniques et 
tres espacés.” It could never be said of Edward and Haime’s 
figured specimen that the monticules are conical and widely 
spaced. Besides, these gentlemen distinctly state the contrary. + 
Nevertheless, since it is probably impossible even if we were 
to ransack the collection of D’Orbigny to say which one of 
_three or four genera he had before him when he wrote the 
* Some ofits more common associates are Callopora rugosa, Amplexopora 
pustulosa, Ceramoporella granulosa, Bythopora delicatula, Hyolithes versail- 
lesensis, Dinorthis retrorsa. This is the Homotrypa bassileri fauna of Nickles. 
+ ‘*Polpier en larges frondes, epaisses de quelques millimetres; mamelons 
arrondis, peu saillants, subradies, large d’un millimetre et demi, et distant 
d'une fois et demi, rarement deux fois leur largeur, presentant a leur sommet 
les plus grand calices: ceux-ci ont un tiers de millimetre, et les plus petits un 
cinquieme."’ Pol. Foss. des Terr, Pal., p. 267. 
