92 PERMIAN FOSSILS. 
abundantly in the dark bluish Limestone near Nosterfield (Geol. Soc., 2d series, vol. iti, 
pp- 108, 119). As German, it is a widely-distributed and well-known species, being 
found at Katterfeld, Schmerbach, Ilmenau, and Thalliter in the Kupferschiefer ; and 
at Grafenheim, K6nitz, Seissla, Kamsdorf, Ropsen, Gliicksbrunn, Wohlsdorf, Gera, 
Ronneburg, and some other localities in the lower beds of the Zechstein. 
PRODUCTUS UMBONILLATUS, King. Plate XI, figs. 14, 15, 16, 17, 18. 
PRODUCTUS UMBONILLATUS, King. Catalogue, p. 8, 1848. 
_ LATIROSTRATUS, Howse. T. N. F. C., vol. i, pp. 256, 257, 1848. 
Diagnosis.—Form subtriangular marginally; plano-convex medio-longitudinally. 
Large valve slightly convex; scantily spinous; with a shallow median furrow ; and a 
small, pointed, more or less projecting umbone, which is flattened on the side adjoining 
the hinge. Small valve nearly flat; with a prominent boss or cardinal muscular 
fulcrum. 
I am not certain but this singular species will eventually be found to belong 
to another genus, perhaps the Awlosteges of Helmerson, supposing it to be really 
distinct from Strophalosia. The flattened space on that side of the umbone adjoining 
the hinge has somewhat the appearance of an area (see the inferior side of the 
prolongation [umbone], on the right side of fig. 18, Pl. XI): but I cannot con- 
vince myself that the part referred to is a true example of this structure: it also 
possesses something like a closed fissure, which, however, I suspect is simply a notch 
in the flattened (or area-like) space, caused by the cardinal boss pressing against it. 
I can say with safety, that it is not furnished with any teeth ; it consequently cannot 
be a Strophalosia. 
I have long considered this species to be distinct from Productus horridus, having, 
in 1843, sent specimens under its present name (which was inserted in my MS. 
Catalogue forwarded at the same time) to my valued friend M. de Verneuil. Productus 
umbonillatus differs from the latter species in its subtriangular form ; in the want of 
ears ; in being considerably less convex; and in having a small poimted beak, without 
any incurvation. 
It is of rare occurrence in the Shelly Limestone at Tunstall Hill and Dalton-le- 
Dale. As yet it does not appear to have been found in Germany, unless a fossil figured 
by Geinitz (Versteinerungen, pl. vi, fig. 3) from Corbusen should prove to be the same 
species. 
