SPONGES, GBAPTOLITES, COKALS. 



85 



Columnaria.] 



This species is readily distinguished from the preceding form (L. typa Winchell 

 and Schuchert) by its thinner corallum, smaller and more unequal corallites, and 

 the obliquity of their apertures. The last is a strongly marked feature of the species, 

 especially near the margins of the corallum. L. typa also occupies a lower horizon 

 in the shales. 



Formation and locality. Galena shales, near Cannon Falls, Minnesota. The type specimen is in the 

 collection of Mr. Ulrich. 



COLUMNARIA (?) HALLI Nicholson. 

 PLATE G, FIGS. 14-16. 



1832. Columnaria alveolata EATON (non GOLDFUSS). Geological Text Book, p. 131, pi. 4. 



1842. Columnaria EMMONS. Geology of New York; Rep. Second District, p. 276, flg. 2. 



1847. Columnaria alveolata HALT, (non GOLDFUSS). Palaeontology of New York, vol. i, p. 47, pi. 12, 



flgs. la-lc. 



1857. Columnaria alveolata BILLINGS. Canadian Naturalist and Geologist, vol. i, p, 124. flgs. 9, 10. 



1863. Columnaria alveolata BILLINGS. Geology of Canada, p. 139, flg. 70, and pp. 938, 954. 



1875. Columnaria alveolata NICHOLSON. Palaeontology of the Province of Ontario, pp. 8, 24. 



1876. Columnaria alveolata ROMINGER. Fossil Corals of Michigan, p. 89, pi. 34, flgs. 1, 2, 4. 



1879. Columnaria (?) halli NICHOLSON. Palaeozoic Tabulate Corals, p. 200. flg. 29, pi. 10, flgs. 3, 3a. 



Description. "Corallum forming large massive colonies which vary from a few 

 inches to several feet in diameter, and which are composed of variously-sized polygonal 

 corallites, in close contact with one another throughout their entire length. The 

 walls of the corallites are not excessively thickened, and they are so completely 

 amalgamated in contiguous tubes that even under the microscope the original lines 

 of demarcation between the tubes can be made out with difficulty or not at all. The 

 large tubes are usually from two to three lines in diameter, though occasionally con- 

 siderably more than this ; and the smaller corallites are of all sizes. Septa marginal, 

 in the form of obtuse longitudinal ridges which vary in number from twenty to 

 forty, do not extend to any distance into the visceral chambers, and are not divisible 

 into an alternating longer or short series. Tabulae strong, horizontal and complete, 

 about half a line apart or sometimes closer. Mural pores not recognized with 

 certainty." 



" I am disposed to doubt very strongly if the present form can be referred to 

 Columnaria at all, and whether it is not truly a perforate coral congeneric with 

 Nyctopora, Nicholson." (Nicholson, op. tit., p. 200.) 



Columnaria alveolata Goldfuss (not Hall) and Favistella stellata Hall, are synony- 

 mous according to Milne-Edwards and Haime, and Nicholson. The latter writer 

 says: "It is quite certain, however, that the Trenton limestone coral just alluded 

 to [C. alveolata of American palaeontologists] is not the form described originally 

 by Goldfuss, and carefully figured by him under the name of Columnaria alveolata 

 (Petref. Germ., pi. xxiv, fig. 7). On the contrary, the latter is almost certainly iden- 



