SUB-GENUS PERONOFORA. 



223 



of J/, decipiens, Rominger, without any necessity for my enter- 

 ing into a detailed verbal comparison. The only point worthy 



Fig. 47. — Minute structure of Monticulipora dccipiens, Rominger, from the Cincinnati Group 

 of Ohio. A, Tangential section, enlarged fifty times ; B, Vertical section, enlarged eigh- 

 teen times. 



of notice in this connection is that Rominger himself recognises 

 (Proc. Acad. Nat Sci. Phil., 1866, p. 116) the similarity of his 

 M. decipiens to M. frondosa, D'Orb., and merely says that it 

 is " more delicate in all respects," and that its "inter-tubular 

 tissue " is less developed. The " delicacy " of the specimen 

 examined is, however, largely a matter of age, while I know of 

 no frondescent species of Monticulipora in which the " inter- 

 tubular tissue " is as largely developed as it is in typical ex- 

 amples of M. dccipiens, Rom. If, however, the name of M. 

 frondosa, D'Orb., should be ultimately abandoned, as given to 

 a form which cannot now be precisely determined, then it is 

 certain that the present species must stand under the title of 

 M. decipiens. 



The form now under consideration is nearly allied to M. 

 mamninlata, D'Orb., in its general conformation; and, when 

 its monticules are well developed, is with difficulty distin- 

 guished from it by a merely superficial examination. It differs, 

 however, wholly from this, as from all other species of the 

 genus, in its minute structure, and therefore needs no detailed 

 comparison with any other form. 



