CerHALopopa. | DEVONIAN MOLLUSCA. 401 
2nd Family. NAUTILIDZ. See page 311. 
Genus. AGANIDES (Mont/.) 
= Goniatites (de Haan.) 
Gen. Char.—Discoid, whorls more or less embracing; septa angularly bent at the edges ; mid-lobe distinct, 
single or double; siphon very small, on the external margin. 
AGANIDES VINCTUS (Sow. Sp.) 
Ref. and Syn.= Goniatites vinctus Sow. Geol. Trans. 2nd Series, Vol. V. t. 54. f. 18. 
= Goniatites insignis Phill. Pal. Foss. f. 228. 
Sp. Ch.—Discoid, compressed; sides of the whorls flattened; periphery broad, subtruncate, obtusely 
rounded, with a narrow cord-like mesial keel; a narrow abruptly-sloped margin to the umbilicus, which ex- 
poses rather more than three-fourths of each whorl; whorls about five, each crossed by about twenty-seven 
obtuse, slightly oblique, obscurely defined, radiating folds, their outer extremities forming each an obtuse 
conoidal tubercle, the two rows of which flank the periphery; rather fine lines of growth mark the surface 
parallel with these ridges; septa, middle lobe long, acutely angular, slightly longer than wide; first sinus 
small, obtusely angular, rounded at its extremity; first Jobe obtusely angular, rounded at its extremity, about 
as wide as the first sinus, and rather less than half the length of the mid-lobe; second sinus rather 
narrower, slightly longer, and more obtusely rounded than the first sinus; second lobe nearly three times the 
length of the first lobe, or one-third longer than the mid-lobe, linguiform, elliptically pointed, acute at its 
extremity; third sinus about as wide as the second, and reaching nearly the same height, sides subparallel, 
end elliptically rounded, obtuse; third lobe semielliptical, one-half the length of the second, its outer edge 
curving obliquely forwards to the umbilicus, forming a nearly rectangular, or slightly acute angle, with the 
nearly straight outer margin; the point of each second lobe extends between the second and third sinus of 
the preceding septum as far as its first lobe. Diameter about four inches, proportional diameter of last 
whorl “, width at mouth at edge of umbilicus <3, at periphery 3). 
It is strange that Professor Phillips did not perceive the identity in form, marking, and septal characters, 
between his Goniatites insignis and the previously described G. vinctus of Sowerby; the slight inaccuracy in 
the representation of the septa in Mr Sowerby’s drawing being easily corrected by an experienced eye, and 
the absence of ridge and tubercles on the outer turn being due to the removal of the shell, and some thickness 
of the cast. The crenulation alluded to by Phillips, on the edge of the septa, is, I think, clearly owing to 
irregular disintegration ; his diagram of the third lobe of the septa is not sufficiently angular, but it is correctly 
represented on several parts of the shell. The resemblance to the G. swbornatus of Miinster alluded to by 
Sowerby is very strong, but that species seems to have more numerous and more gradually tapering whorls, 
the body-whorl forming a smaller proportion of the diameter, and to be without keel, as well as the differences 
in the form of the septa. 
Position and Locality.—Rare in the Olymenia limestone of S. Petherwin. 
Genus. CLYMENTA (Miinst.) 
Syn. = Endosiphonites (Anst.) 
Gen. Char—Shell discoid, whorls usually exposed, in contact ; septa with a deep angular lobe on each 
side, middle portion nearly straight; siphon at inner edge. 
CLYMENIA BISULCATA (JZiinst.) 
Ref—Beitriige zur Petrefactenkunde, 3 Heft. t. 16. f. 6. 
Sp. Ch.—Discoid, compressed, five to six whorls; gently convex on the sides, with a shallow, wide furrow 
on each side, strongly defining the narrowed, square, prominent periphery; margin of the umbilicus steep, 
rounded; whorls nearly flat, concealed ; surface with strong, slightly irregular, subequal, sigmoidal strize on the 
3 
[easc. 11] 
