SUB GENUS DIPLOTRYPA. 165 



" maculce," and, above all, by the peculiar perforated or in- 

 complete tabulze of the large tubes, by the presence or absence 

 of which thin sections of either form may be at once dis- 

 tinguished. 



I have named the species after my friend Mr Whiteaves, 

 the accomplished paleeontologist of the Geological Survey of 

 Canada. 



Horizon and Locality. — Not uncommon in the Trenton 

 Limestone of Peterboro', Ontario, in association with I\I. Scl- 

 wynii, Nich. 



Monticulipora (Diplotrypa) calycula, James. 



(PI. IV. figs. 4-4<^.) 



Lickaialial calycula, James, Cat. Foss. Cincinn. Group, 1871 (named, but 



not figured or described). 

 Clixtcfes'l calycula, James, Cat. Foss. Cincinn. Group, 1875, P- i- 



Spec. C//<r?r.— Corallum free, forming a thin, circular, con- 

 cavo-convex, leaf-like expansion, of about i-6oth inch in thick- 

 ness, and from half an inch to nearly two inches in diameter. 

 The under surface is in general deeply concave, and Is covered 

 with a thin epitheca, which shows fine radiating striae, and 

 occasionally a few concentric wrinkles. Upper surface carry- 

 ing the calices, which (according to James) are oval or circular 

 in shape, and are not disposed so as to form clusters or " mon- 

 ticules." Ordinary corallltes of two kinds, large and small. 

 The large corallltes are oval, from i-75thto i-8oth inch in their 

 long diameter, rarely In contact, and then only touching each 

 other at limited points. The small corallltes are variable in 

 shape and size, more or less angular in outline, and wedged 

 in at all the interspaces left between the large oval tubes. 

 In addition to the two sets of normal corallltes, there is an 

 abundantly developed series of thick-walled, somewhat quad- 

 rangular tubuli (" splniform corallltes "), which are mostly 

 situated at the points where the large oval corallltes would 



