296 
DEVONIAN FAUNA. 
13. Pleueotomaeia Shaleei, n. sp. PI. XXVIII, figs. 9, 9 a. 
1844. ScHizosTOMA viTTATUM, Goldfuss. Petref. Germ., vol. iii, p. 79, pi. clxxxviii, 
fig. 6ffl, h. 
? 1853. Pletjbotomabia euomphalxjs, Sandberger. Verst. E-hein. Nassau, p. 187, 
pi. xxii, figs. 12, 12 a, b. 
Description. — Shell rather small, discoidal, very short. Spire flat, of four or 
five slowly increasing whorls. Suture apparently very deep, facing upwards. 
Whorls sab-circular in section, rising convexly from the suture to their highest part, 
where there is an excavated flat sinus-band, about one-fifth the width of the whorl, 
and bounded by sharp edges. Ornament consisting of close fine lines or threads, 
arching backwards from the suture, curving round in the sinus-band, sloping 
forward below it and gradually becoming perpendicular on the back. Back of the 
whorl flatly convex. 
Size. — Height about 5 mm., width about 21 mm. 
Locality. — There are two badly preserved specimens in the Torquay Museum 
which probably came from Lummaton, and another, equally indistinct, in the 
Woodwardian Museum from the same locality. 
Bemarhs. — The specimens from which the above description is taken are in a 
very unsatisfactory state of preservation. Their surface is so decayed and 
damaged by matrix that it is most difficult to make out the character of the 
ornamentation. They appear to be very similar to Schizostoma vittatum, Goldfuss, 
and most probably belong to the same species, although one or two differences may 
be observed in that Eifelian shell, e. g. its sinus-band seems broader and not sunk 
below the rest of the surface, and its striae seem to be finer. 
Pleurotomaria euomphalus, Sandberger,^ seems at first sight to correspond 
exactly with our shell, but it differs from it in the one important point of having 
a raised sinus-band between two slight furrows. This point is not very clearly 
shown in Sandberger's figure, and, but for this, the resemblance between the two 
species is so great that they would certainly be placed together. 
The name PI. mttatar was used for a very difi'erent shell by Phillips some 
years before Goldfuss named the present shell, and consequently a fresh name 
must be found for the latter. It does not seem safe to use Sandberger's name in 
consequence of the difference mentioned above ; I therefore propose to rename it 
after my friend Professor H. Shaler Williams, of Cornell University, one of the 
foremost American workers in Devonian Geology. 
^ 1853, Sandberger, ' Verst. Ehein. Nassau,' p. 187, pi. xxii, figs. 12, 12 a, b. 
•-' 1836, Phillips, ' Geol. Torks.,' pt. 2, p. 228, pi. xv, fig. 24. 
