A CONTRIBUTIOX TO THE LoWER DEVONIAN FaUNAS OF MARYLAND 35 



by the aperture. It is referred, with hesitancy, to this species ; the absence 

 of the spire making identification uncertain. 



Occurrence.— Rblde^berg Formation, New Scotland ]\Iember. 

 Corriganville. 



Collection. — U. S. National Museum, 



Platyceras multisinuatum Hall 

 Plate LXXXA^ Figs. 4-6 



Platyceras multisinuatum Hall, 1859, Nat. Hist. N. Y., Pal., vol. iii, p. 319, pi. 

 Iviii, figs. 8a. b. c, and 9a. b. 1861. 



Description. — " Shell subdiscoid in the young state; apex nearly on a 

 plane with the outer volution : volutions about three, the first ones minute ; 

 outer one becoming free, ventricose, rounded or scarcely angular helow, 

 somewhat flattened on the upper side, marked by several ridges and shallow 

 depressions on the upper and dorsal sido : aperture somewhat longitudi- 

 nally oval; peristome sinuate, with a deeper sinuosity on the anterior 

 margin. Surface marked by fine transverse stria?, which are strongly un- 

 dulated on the inequalities of the shell, and crossed by fine longitudinal 

 or revolving stria?." Hall, 1859. 



A single individual has been observed which shows as nearly as can be 

 seen, the features in the above description. Although this specimen is 

 fragmentary, the peculiar markings of tlie species leave no doubt as to the 

 identity of the former. The revolving stria? are not observable. 



Occurrence. — Helderberg Formation, New Scotland Member. 

 Cumberland ? 



Collection. — George M. Eoeder. 



Platyceras platystomum Hall ? 

 Plate LXXXV, Fig. 7 



Platyceras platystomum Hall, 1859, Nat. Hist. N. Y., Pal., vol. iii, p. 326, pl. 

 Ix, figs, la, b, 2; pL Ixi, figs, la, b, c, 1861. 



Description. — " Shell obliquely depressed conical, arcuate on the upper 

 part of the first volution ; the apex obtuse, consisting of about a single close 



