CreHatopopa. ] UPPER PALAXOZOIC MOLLUSCA. 563 
from the V. tuberculatus (Sow.), which is the only allied form. In the figure in the Mineral Conchology of 
Nautilus tuberculatus (t. 249) there is an apparent concavity of the section of the periphery; but as this did 
not agree with the inner outline, I doubted its correctness, and on writing to Mr Sowerby he very kindly fur- 
nished me with the exact form of the section of the original specimen, proving that the periphery is convex, and 
regularly rounded, contrasting in the strongest manner with the present species, which also wants the medial 
line of the VV. tuberculatus. I have only indistinctly seen the septa, which seem to be regular, moderately arched, 
and rather close. The position of the siphon is unknown. 
Position and Locality.—Very rare in the carboniferous limestone of Derbyshire. 
Explanation of Figures.—P1. 8. H. fig. 15, transverse section of whorl, natural size; fig. 15 a, view of 
periphery, reduced one half in diameter ; fig. 15 5, side view of half of last whorl, reduced half a diameter. 
Genus. AGANIDES. See p. 401. 
AGANIDES Barpotanus (JZ. V. K. Sp.) 
Ref. and Syn. = Goniatites Barbotanus M. V. K. Geol. Russ. t. 27. f. 3. 
Dese.—Globose, whorls greatly embracing, umbilicus very minute, or closed ; surface crossed by very fine, 
flat, slightly sinuous strie; greatest thickness near the inner edge of the whorls; periphery very broadly 
rounded convex ; sides very slightly convex, sometimes slightly compressed ; mouth transversely lunate ; septa 
moderately numerous; mid-lobe long, rather narrow, trifid, but not very deeply notched, extending as far back 
as the upper edge of the first lateral sinus of preceding turn ; first lateral sinus very large, much wider than the 
mid-lobe, semicireularly arched at its anterior extremity; first lateral lobe small, linguiform, pointed, shorter 
than the mid-lobe, extending slightly farther back than the upper edge of the first lateral sinus ; second lateral 
sinus as broad as the first, semicircularly arched into the umbilicus. Diameter 9 lines, diameter of umbilical 
depression ;{;, width at inner edge of mouth 7. 
This species much resembles the Goniatites micronotus and G. implicatus of Phillips, but is distinguished 
by its more globose form, by the mid-lobe not extending within the level of the first lateral sinus on each side of 
the preceding septum. Our specimens have the depression marking the umbilicus slightly larger than in the 
figure of the Geology of Russsia; but as this character varies in all the allied species, I have no doubt of the 
identity of the form; the mid-lobe agrees exactly with the septa as represented on the above figure 34, rather 
than with the magnified septum 3c, in being narrower and less deeply cleft than the latter. Two specimens 
in the collection of Count Miinster, marked Yorkshire, though more probably Isle of Man, bear the manuscript 
name Goniatites Vernewil. 
Position and Locality—Not uncommon in the black carboniferous limestone of Isle of Man; rare in the 
carboniferous limestone of Craige, near Kilmarnock. 
AGANIDES CARBONARIUS (Sow. Sp.) 
The original specimens in the collection, from the Culm limestone of Venn, Swimbridge, described 
by Sowerby under the name Gioniatites carbonarius, in the Transactions of the London Geological Society 
(2nd Series, Vol. V. t. 52. p. 89), are fragments, the specific characters of which cannot be recognised ; and 
the name (even if it had not been used by continental writers for a different species) should he erased from 
our lists. 
AGANIDES DIADEMA (Gold. Sp.) 
Ref. and Syn. = Goniatites (Ammonites) diadema (Gold.) ; Dumont, Dese. de Liege, p. 356 ; Beyrich, Goniat. 
t. 2. f.8 to 10; 2+ Goniatites striolatus Phill. Geol. York. Jol. 1. t. 19. f. 15 to 18. 
Desc.—Discoid, periphery very convex, broadly rounded, sides gently convex, more or less flattened, the 
width being very variable (but greatest in the young of all varieties); umbilicus rather large, deep, with 
an angular, prominent margin, which is either smooth or crenulated by the ends of the transverse striz ; 
