NO. 1323. STR UCTURAL FEA TVRES OF HOMOTR YPA—BASSLER. 579 



than 3 mm. in thickness. Surface smooth, with maculae of decidedly- 

 larger zocecia. Apertures thin wailed, direct, eight to nine in 2 mm. 

 Acanthopores not ob.served at the surface. Mesopores of not infre- 

 quent occurrence both in the maculge and among the ordinary zooecia. 

 Internal characters: Diaphragms practically wanting in both regions. 

 Axial region with thin crinkled walls, which are but slightly thiciened 

 in the short peripheral zone. A series of generally four cystiphragms 

 is developed in the peripheral region of each zooecial tube. Acantho- 

 pores rather few and inconspicuous, generally situated at the junction 

 angles of the zooecia. 



The smooth, thin, flat fronds will distinguish this neat species from 

 the associated 11. hassleri. There is no other species sufiiciently 

 related to require comparison. 



Occurrence. — Not uncommon in the Warren beds of the Lorraine 

 formation at Lebanon, Ohio. 



Cat. No. 34329, U.S.N.M. 



HOMOTRYPA FRONDOSA, new species. 



Homotrypa frondosa (neither Montlculipora frondosa D'Orbigny nor Chxteles 

 frondosus Edwards and Haime.) Cumings, American Geologist, XXIX, 

 1902, p. 208, pi. X, figs. 11, 12; pi. xr, figs. 2, 5; pi. xii, fig. 1. 



In 1850 D'Orbigny proposed Monticuli'pora frondosa.,'^ based on 

 specimens said to have been found at Cincinnati and Oxford, Ohio. 

 In 1851 Milne-Edwards and Haime redefined and figured the species 

 as Chsetetes frondosus,^ basing their description it seems upon the same 

 specimens used by D'Orbigny. Since the internal characters are not 

 described in either case, and as there are several forms of different 

 genera with which 31. frondosa might be identified, it is probably 

 impossible without the aid of the type specimen to definitely fix upon 

 D'Orbigny's species. The status of the species was further complicated 

 by Nicholson in redefining D'Orbigny's Montlculipora onammtdata^'^ 

 since, as shown later by Ulrich, he really described a species more like 

 M. frondosa. Recently Cumings identified D'Orbigny's, or rather 

 Edwards and Haime's, species with a rare form of Iloraotrypa., found in 

 the "very top of the Lorraine or base of the so-called Richmond 

 formation. " 



An effort to find D'Orbigny's type specimens is now being made, and 

 should this succeed the standing of his species will be adjusted. How- 

 ever, for the present I prefer to adhere to Ulrich's identification of 

 Monticuliixjra frondosa, and Cumings's Homotrypa frondosa is here 

 recognized as a new species, preserving that writer's name. 



«Prodr. de Pal., I, p. 25. 



&Pol. Foss. Ter. Pal., 1851, p. 267, pi. xix, figs. 5, 5a. 



cQuar. Jour. Geol. Soc. London, 1874, p. 508. 



