110 The American Geologist. August, 1893 
by Owen is ;i Strombodes. The species is ;i good one, the 
differences between it and all other described species of the 
genus being very marked. Moreover, the species may still be 
collected in the same locality and at the same horizon whence 
Owen'- specimen was obtained. Figure 5, plate v. illustrating 
this paper, is reproduced from a photograph of an individual 
which exhibits the exact characters shown in Owen's excel- 
lent figure. 
The species considered by Billings in the Canadian Journal 
for IN")'.), page 12s. is that which has come to be recognized 
as Phiilipsastrea gigas. Its affinities are with Heliophyllum 
and Acervvlaria, and it is not known outside the Corniferous 
and Hamilton divisions of the Devonian. On the other hand, 
Strombodes gigas, the species described by Owen as Astrea .' 
gigas, has iits affinities with Chonophyllum and Ptychpphyllum, 
and its range is in the lower part of the Niagara Limestone, 
as the assemblage of strata bearing this designation is devel- 
oped in Iowa. 
The form that we have recently been calling Phillipsastn a 
gigas Owen, on the authority of Billings,* Rominger,f Nichol- 
son^ and Davis§, is a well marked and easil} 7 recognized 
species, but owing to the error in identifying it with Owen's 
Niagara species, Strombodes /////"-v. it remains without proper 
specific designation. The form is somewhat common a few 
feet above the horizon characterized by Spirifera pennata 
Owen, in Johnson and Linn counties and the southern half of 
Buchanan, in Iowa. For this magnificent species I propose 
the name Phiilipsastrea billingsi. Figures 1 and 2, plate vi, 
will show the general features of the species so far as relates 
to details of structure. 
The species discussed in this paper should stand as follows: 
I'l j eliopli) Hum expaiisum Owen. 
Plate v, Figs. 1-4. 
Anthophyllum expansum Owen. Report on Mineral Lands, 1844, p. 
69. Plate xin, Fig 3. 
Cyathophyllum corintheum Owen. Report on Mineral Lands, 1844. 
p. 69. Plate xin, Fig. 6. 
*Canadian Journal for 1859, p. 128. 
^Michigan Fossil Corals, p. 129. 
XPal. of Ohio, vol. n, p. 241. 
%Kentticky Fossil Corals, plate 118. 
