On the Genus Monticulipora. 



31 



septate, parallel flattened tubes, the apparent septan marking the origin 

 of the chalices; intersections of the ridges and stride mostly at right 

 angles; chalices, or net-work of chalicular apertures, almost regularly 

 quadrangular, somewhat more delicate and condensed where worn than 

 the preceding species, from which it is furthermore distinguished by 

 rythmical swellings upon the surface, or light tuberculations, upon 

 which the chalices are larger and more irregular in form; number of 

 chalices in a space of two lines square, about one hundred. It must 

 have belonged to a specimen from at least four to six inches in length 

 and width, as the concentric ridges upon it are so gently curved as to 

 show a great relative distance from the center.'' 



It is plain, from this description, that Dr. Prout had a specimen 

 that was split, showing the membrane that separates the two halves of the 

 corallum, and notwithstanding Prof. Nicholson has never seen any such, 

 it is a fact that split specimens, showing the concentricall}' wrinkled cal- 

 careous membrano upon either half, are not rare, but, on the contrary, 

 more frequently occur than split specimens of any other bryozoan found 

 in the Hudson River Group. In 1877, in the Catalogue of American 

 Palaeozoic Fossils, I followed Dr. Prout in referring this species to the 

 Bi^ozoa, under the name of Cyclopora jamesi. I have no doubt that it is 

 a biyozoan, and, unless the genus Cyclopora shall be subdivided, and 

 another species taken as the type, it will remain in that genus. As 

 pavonia has priority as a specific name, it should be called Cyclopora 

 pavonia, unless it is made to appear that D'Orbigny described another 

 form. I have never seen either D'Orbigny's work, or the Pol. Poss. des 

 Terr Pal., of Edwards and Haime, and hence accept the name pa- 

 vonia on the authority of others. I was not aware, however, that any 

 one had classed the form with the Ptilodictya until I learned it from 

 the book under review. The observations upon this species by Prof. 

 Nicholson strongly reminds one of the story of the man who did not 

 believe that water could be frozen into ice, because he had never seen it 

 done, and it may be laid down as a general rule, that where an author ig- 

 nores the writings and observations of others, and depends upon lim- 

 ited information and experience from which to draw generalizations, 

 we may expect some mistakes; and if he describes new species of 

 fossils, the flood of synonyms will be limited only by his means of 

 publication. 



Chetetes briarens is now Monticulipora (Monotrypa) briarea. 

 Chetetes corticans is abandoned as a S3'non3'm for Monticulipora 

 tuberculata, which he refers to his subgenus Monotrypa, though 



