300 SYSTE:\rATic Paleoxtology— Middle Devoxiax 



Subclass EUTHYNEURA 

 Order OPISTHOBRANCHIA 



Suborder PTEROPODA 

 Family CAVOLINIIDAE 



Genus STYLIOLINA Karpinsky 



Styliolina fissurella (Hall) 

 Plate XXXVII, Figs. 17-20 



Tentaculites fissurella Hall, 1843, Geol. N. Y., pt. iv, p. 180, figs. 9, 10 and p. 



222, fig. 4. 

 Styliola fissurella Hall, 1879, Pal. N. Y., vol. v, pt. ii, p. 178, pi. xxxl A, figs. 



1-2S. 

 Styliola (.Styliolina) fissurella Clarke, 1885, Bull. U. S. Geol. Surv., No. 16, 



p. 57. 

 Styliolina fissurella Clarke, 1891, Am. Geol., vol. viii, p. 88. 

 Styliolina fissurella Clarke, 1892, Am. Jour. Sci., 3d ser., vol. xliii, p. 58. 

 Styliolina fissurella Clarke, 1898, Fifteenth An. Rep. State Geologist [N. Y.], 



p. 54. 

 Styliolina fissurella Grabau, 1899, Bull. Buffalo Soc. Nat. Sciences, vol. vi, 



p. 282, fig. 214. 

 Styliolina fissurella Clarke, 1903, N. Y. State Mus., Bull. 65, p. 570. 

 Styliolina fissurella Clarke, 1904, N. Y. State Mus., Mem. 6, pt. 2, p. 342. 

 Styliolina fissurella Grabau and Shimer, 1910, N. Am. Index Fossils, vol. ii, 



p. 16, fig. 1229. 



Description. — " Form an extremely slender, elongate cone, like the 

 point of a small needle ; apical portion of the tube solid ; apex extremely 

 minute, often bulbiform, and very gradually enlarging to the mouth. 

 Surface often smooth and without any visible ornamentation, so far as 

 can be determined ; or with fine striae of growth, which are unequally de- 

 veloped on different parts of the shell; also with fine longitudinal striae, 

 which may be present with or without transverse striae ; usual length from 

 one to two, sometimes two and a half, and rarely five millimeters." Hall, 

 1879. 



The ]\Iaryland specimens are smooth impressions except that the larger 

 ones show very faint remains of transverse striae and a longitudinal 

 depressed line along the central part of the shell which is probably due to 

 pressure. This species is noted only infrequently in the Maryland Hamil- 



