GRABAU: MONILOPORIDAE. 
413 
Formation and locality. From the calcareo-arenaceous Platy- 
crinus beds of the Keokuk group, lower Carbonian, Crawfordsville, 
Indiana. 
Named in honor of Prof. C. E. Beecher of Yale university. 
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Types in the collection of Yale university museum, New Haven, 
Conn., and in the collection of the Museum of comparative zoology, 
Cambridge, Mass. 
Moxilopora axtiqua AVhiteaves. 
Monilopora antiqua Whiteaves, Contrib. Can. pal., 1898, vol. 1, 
pt. 5, p. 364, pi. 48, figs. 1, 2, 3, 3a. 
This species was described from the Hamilton group of Thedford, 
Ontario, where it is said to be not uncommon. It is the first and 
only species so far described from rocks below the Carbonic, in this 
country, and none have been noted at so low a horizon elsewhere. 
Dr. AVhiteaves states that the species is “ at first attached to and 
either wholly or partially encircling foreign bodies, but apparently 
free and ramose ultimately.” Like the other species it is found 
chiefly on crinoid stems, “completely enveloping them, except at 
the ends, and throwing out corallites in all directions.” This method 
of growth therefore may be regarded as characteristic of the genus. 
Free branches occur in this species as in those from the Carbonic 
rocks, and in them occurs the zigzag, alternate arrangement of the 
corallites found in the other species. A method of growth, not yet 
observed in the other species, is shown (AVhiteaves, loc. cit., fig. 2) 
where a partially attached specimen spreads out into a “ thin, nearly 
fiat, sub-circular lateral expansion, with all the corallites springing 
from its upper surface, and the lower surface consisting of a con¬ 
centrically wrinkled epitheca.” 
The surface of the corallites “ * * * is minutely granulo-striate 
and marked by irregularly disposed and very minute granules, 
tubercles, or low, interrupted longitudinal ridges, with equally 
minute grooves or channels between them.” This feature readily 
distinguishes the species. 
The occurrence of this species in Hamilton strata is of great 
interest, as showing that the family, as at present constituted, was 
fully differentiated in Mesodevonian time. 
