402 BRITISH PALAXOZOIC FOSSILS. [CepHaLopopa. 
sides, which are abruptly bent backwards at the outer lateral furrows, to form a deep retral lobe on the flat 
projecting periphery; seven striz in one line on the periphery, about ten in the same space on the sides ; 
siphon very small, at the inner edge. Diameter about one inch, proportional diameter of mouth ;;;, width of 
umbilicus “4, width of mouth ;;. 
According to Miinster the septa have got a sharply angular side lobe, somewhat as in C. undulata. The 
species is very strongly marked by the two broad sulci, defining the prominent, narrowed, flat periphery from 
the convex sides. I have only found a fragment of the last and penultimate whorl in the limestone of S. 
Petherwin. 
Position and Locality —In the limestone of S. Petherwin. 
CLYMENIA L&VIGATA (Miéinst.) 
Ref.—Minst. Ann. des Sc. Nat. 2nd Series, Vol. IT. t. 1. f. 1. 
Sp. Ch.—Discoid, compressed, of about seven or eight very gradually increasing, moderately convex 
whorls, scarcely one-fifth of which are concealed by the succeeding turn; surface smooth, or with a strong lens, 
fine obsolete transverse strize of growth crossing the whorls; periphery obtusely rounded ; section of each whorl 
regularly oval, the outer turns slightly more compressed than the inner; septa with the middle portion forming 
a widely-arched mid-sinus (not lobe); sides forming a very broad obtusely-rounded first lobe, the inner ex- 
tremity of which reaches the umbilicus at about the same height as the mid-sinus; siphon forming a thick 
funnel-shaped inflection of the inner margin of each whorl, extending half way to the next septum. Diameter of 
moderate-sized specimen two and half inches, proportional diameter of last whorl 3, proportional thickness =. 
This species is perfectly identical in all respects with that so common at Schubelhammer ; in one imperfect 
fragment, and in one of Count Miinster’s specimens, I fancied I saw traces of the thread-like keel, but a number 
of more perfect specimens shew nothing of the kind. D’Orbigny places this species in the genus Trocholites. 
Position and Locality—Not uncommon in the Devonian limestone of S. Petherwin ; a compressed specimen, 
probably of this species, found by myself in the higher part of the slates of Lanlake, Launceston. 
CLYMENIA MUENSTERI (J7°Coy). Pl. 2. A. fig. 12. 
Ref. and Syn. = Endosiphonites Ansted, Camb. Phil. Trans. Vol. VI. t. 8. f. 1; M°Coy, Ann. Nat. Hist. 
2nd Series, Vol. VIII. 
Sp. Ch.—Discoid, compressed ; periphery slightly narrowed, subtruncate, obtusely-rounded, with a faint. 
narrow mesial keel, sides of the whorls flattened, with a steep narrow edge to the umbilicus, in which nearly 
three-fourths of each whorl is exposed; whorls upwards of six, all crossed by obsolete radiating ridges, each 
terminating at the edge of the umbilicus in a sharp, elongate, plait-like tubercle, and terminating at the distal 
end in an obscure, thick, conoidal tubercle; about twenty-six ridges and pairs of tubercles in each whorl; siphon 
very thick, close to the inner edge ; septa with the middle portion nearly transverse, scarcely convex ; first sinus 
scarcely marked, obtusely rounded ; first lobe deep, semicircularly rounded; twice as wide as long, forming 
nearly a right angle with the second sinus, which is slightly oblique towards the umbilicus but nearly flat; a 
straight line drawn from the centre touches the top of the first and second sinus. Diameter three inches nine 
lines, proportional diameter of last whorl =, width of mouth near edge of umbilicus ;;, width of periphery 55. 
This is one of the largest Olymeni@ known, and most closely resembles the Clymenia binodosa of Miinster’s 
Beitrage zur Petrefactenkunde for 1839, t. 2. f.3; but that species has the last whorl very much smaller in 
proportion to the diameter (>), has the periphery as broad as any other part of the whorl, and has consequently 
a considerably wider middle portion; otherwise in the form of the septa, general shape, and ornament, the 
species are closely allied, the ridges and tubercles in the British species being rather more numerous and less 
prominent. 
Position and Locality—Very rare in the Clymenia limestone of S. Petherwin. 
Explanation of Figures—P1. 2. A. fig. 12, natural size; fig. 12 a, profile of mouth, and portion of peri- 
phery of penultimate whorl ; fig. 12 4, line of septum. 
