NO. 1908. NEW SILURIAN MOLLUSCA FROM MAINE—WILLIAMS. 383 



Apulia [ = Hamilton formation], Onondaga County, N. Y., tab. 

 No. 22, Ithaca," but not figured. The specific name was spelled 

 suhulata in the list* given by Conrad. The same spelling is used in 

 referring to it in tiie list of species of the Hamilton in Vanuxem's 

 final report.- In the final report on the Paleontology of New York 

 State ^ Hall figured this species under the name ModiomorpJia suh- 

 alata, referring it to the genus Modiomorpfui which he had described 

 antl named in 1870.'' 



In reporting tliis Eastport fauna in 1905 Williams * recognized 

 Shaler's reference of this species to the genus Modiomorpha and ten- 

 tatively to the species of suhulata Conrad, and it was upon tliis identi- 

 fication that the Devonian age of the formation was inferred. In the 

 same paper Schuchcrt listed species from Carlow Island and north 

 end of Moose Island under the names ''WJiiteavesia sp. new," "Modlo- 

 lopsis sp. undetermined," and " Psiloconchoid pelecypod." In the 

 first case it was associated ^\^th "Leperditia of the L. alia ty})e," 

 thus bringing in a new means of correlation. Schuchcrt rightly 

 determined the age as "unmistakably Siluric and beneath the 

 Helderbergian.® 



Later investigations have fuUy confirmed the correctness of 

 Schuchert's conclusion that the Carlow Island and Moose Island 

 faunas are alike, and the same species of Eurymydla occur in both. 



Critical examination of a large number of specimens brought 

 together in the recent survey of the Eastport quadrangle has made it 

 clear to the writer that these Eastport modiolopsoid forms difi'er from 

 both Modiomorpha Hall' and Modiolopsis Ilall^ in the absence of a 

 median sulcus in front of the umbonal ridge. In tliis particular they 

 agree with McCoy's genus Anodontopsis^ and Ulrich's genera ]V7iite- 

 avesia *" and Eurymya}^ The mistake in generic reference of the species 

 made by Shaler and Williams (as probably also by others) was due 

 to the fact that the larger specimens are often grooved in the place 

 of the natural median sulcus of Modiomorpha and Modiolopsis, due 

 (as has been learned by careful inspection) to the crushing of the 

 very fragile shells. Sucli sjiccimens show the shell to have been 

 cracked along this line, but when uncrushcd the shell is found to have 

 the ventral margin convexly curved throughout and has no byssal 



1 5th Ann. Rept. Geol. Surv., New York, 1S41, p. 30. 



» N. Y. Gcol., 3d District, 1S42, p. l(i2. 



•Nat. Ilist. N. Y., vol. 5, pt. 1, Lamellibranchuata, II, 18S5, p. 2S3, pis. 35 and 39. 



* Prel. notice. Lain., Shells, pt. 2, 1S70, p. 72. 



• U. S. Geol. Surv., Prof. Paper 35, p. 24. 

 •Idem., p. 26. 



' Hall, J., Prel. notice. Lam., Shells, pt. 2, 1870, p. 72. 



« HaU, Nat. Hist. N. Y., Pal., vol. 1, 1847, p. 157. 



» McCoy, F., Ann. and Map. Nat. Hist., scr. 2, vol. 7, 1S51, p. 5J. 



'« ririch, E. 0., Geol. and Nat. Hist. Surv. Minnesota, Final Report, 1804, p. 513. (Note: in the text the 

 nameused Is j4c//nomya, biiton page 628 the name MltUeavesia is substituted for ..4c/i7iomyo, which w-as 

 found to be preoccupied.) 



«» Ulrich, idem, p. 512. 



