22 GEOLOGICAL AND NATURAL HISTORY SURVEY OF CANADA. 



supporting object has decayed, and loft a clear and distinct imprc8.sion of 

 even its most fino markings in the membranacooiis opithoca of the 

 zoarium." There is one circumstance which makes the writer hositato to 

 concur in Mi*. Ulrich's opinion that Spatlopora areolata was parasitic 

 upon a Pasccolus, and that is the fact that the former lias been found only 

 in the lower bods of the Trenton formation, in which Pasceolus docs not 

 occur; the latter is found only in the Wj7/)er shaly beds of the Tronton, 

 about 180 feet above the lower onc^, and near the horizon of the Utica 

 Formation. 



Ijocaliti/ and Funn 'tion. — Hull, Q ic., in the lower bods of the Trenton 

 Formation. 



GoUectors.—^Viihcv II Billings, II. M. Ami, A. II. Foord. 



StELLIPORA ANTIIELOIDEA, Ilall. 



Slcllijwra anlhdoidca, Hall, Pal., N.Y., Vol. I., p. 71), pi. XXVL, ii-s. ll)a, 106, 



1847. 

 Stdllpora auiheloldecty D'Orbigny, Prodr. dc Paleont, t. 1, p. 22, 1850. 

 GonstcUaria anthcloidea, Edwards and JIaime, Pol. P'oss. des Terr. Pal., p. 270, 



pi. XX., figs. 7-76, 1851. 

 Constellaria anthdoidea, Nicholson, Pal. of Ohio, Vol. II., p. 214, 1875. 

 ConsfeUaria anthdoidea, Nicholson, Ann. Nat. Hist., sor. 4, Vol. XVII I., p. 92, 



pi. v., fig. 10, 187G. 

 LocaHty and Formation. — Ottawa City. Trenton Formation. Two 

 fragments of this species, imperfectly preserved, have boon identified. 

 (7o//6T/(?r.— Walter R. Billings. 



Constellaria Florida, var. plana, Ulrich, MS. 



This species has been identified by Mr. Ulrich. 



Locality and Formation. — Ottawa City. Trenton Formation. 



Collector.— Yj. Billings. 



II. On some preciously unrecorded Species of Ptllodlctya, Stlctojiora, and 

 Arthronema, from the Trenton Formation. 



Ptilodictya pavonia, D'Orbigny. 



riilodictya ijavonia, D'Orbigny, ProJr. de Paleont, Vol. 1, p. 22, 1850. 



Choeietes pavonia, Milne-Edwards and Haime, Pol. Foss. des Terr. Pal., p. 267, 



pi. XIX., figs. 4, 4a, 1851. 

 Choetetes pavonia, Pominger, Proc. Acad. Nat. Sci. Phil., 1866, p. 116. 

 Siiciopora clathratida, James, Cat, Foss. Cincinnati Group, 1871. 



