Maryland Geological Survey 213 



Favosiies basaltica Billings, 1859, iMd.. p. 106, fig. 8. 



Calamopora epidermata Rominger, 1862, Amer. Jour. Sci., 2d ser., vol. xxxiv, 



p. 396. 

 Favosites Gothlandica Nicholson, 1874, Pal. Ont., p. 45 (with reference only 



to the coral from the Corniferous limestone and Hamilton formation). 

 Favosites Forbesi Nicholson, 1874, Pal. Ont., p. 48, pi. vii, fig. 8; pi. viii, fig. 4. 

 Favosites Forbesi var. tuberosa Nicholson, 1879, Pal. Tab. Corals, p. 62, pi. iii, 



figs. 2, 2a-e. 

 Favosites epidermatus Rominger, 1876, Geol. Survey Mich., Foss. Corals, p. 



28, pi. viii, figs. 1, 2, 3. 

 Favosites tuberosus Rominger, 1876, ibid., p. 30, pi. ix, figs. 1, 2. 

 Favosites tuberosa Hall, 1876, Illus. Dev. Foss., pi. vi, fig. 6; pi. viii, figs. 1-7. 



pi. xi, fig. 1; ibid., var., pi. i, fig. 1; pi. iv, fig. 1; pi. vii, fig. 1. 

 Favosites epidermata Hall, 1876, Illus. Dev. Foss., pi. vi, figs. 1-5; pi. xii, 



figs. 6, 9-13; ibid., var. corticosa. pi. x, figs. 1-6; pi. xi, figs. 11, 12. 

 Favosites tuberosa Whiteaves, 1889, Contr. Can. Pal., vol. i, pt. ii, p. 121. 

 Favosites basaltica Lambe, 1889, ibid., vol. iv, pt. i, pp. 8-10; pi. i, figs. 3, 3a. 



Description. — Corallum subhemispherical, consisting of numerous 

 closely united prismatic corallites, epidermis not observed. Corallites 

 subequal in size, their walls moderately thick. Mural pores in several 

 rows, diameter of pores about 0.3 mm. Tabulae often fiexuous, close, dis- 

 tance between tabulse about 0.5 to 1 mm. Squamulae large, numerous. 



Diameter of larger corallites 2.5 to 3 mm. 



The limits of the species F. goihlandicus and F. basalticus are very 

 insecure. Nicholson regards the more diagnostic distinctions to be that 

 F. gothlandictis has corallites of subequal size with thin walls, while F. 

 basalticus {F. forhe.si according to Nicholson) has very unequal corallites 

 with thicker walls. He records both species in the Silurian and the 

 Devonian. Lambe distinguishes them by the fact that F. gothlandicus 

 has spines while F. hasaUicvs has squamulae in corallites and restricts the 

 former to the Silurian and the latter to the Devonian. 



The presence or absence of squamula is, however, not a trustworthy 

 diagnostic since Lambe remarks that squamuliE are often not preserved in 

 F. basalticus while Nicholson cites squamulas in Silurian species and 

 spines in Devonian species of Favosites. A single specimen has been ob- 

 served whose exact stratigraphic position is not known. Its corallites are 

 subequal but bear numerous squamulfE upon their walls. 



Occurrence. — Helderberg Formation. Near Cumberland. 



Collection. — Marvland Geological Survey. 



