SUPPLEMENT. 
327 
ated uear the margin, either at the apex of the triangle (Orth. 
Biichi, de Tern.) or at its base (Orth. trianguJare, d’Arch. and 
de Tern.); or, again, it may be nearly central (^^ Gomphoceras” 
hesperis, Eichw.^) ; in all cases it lies in the median line of the 
dorso-ventral diameter. It is generally nummuloidal, rarely cylin- 
drical ; in the former case it is filled with radiating deposits. The 
septa are very crowded ; their sutures form a broad and shallow 
sinus on the ventral side of the shell (fig. 50 a), and arching upwards 
at the lateral angles bend slightly backwards, and then forwards on 
the opposite (dorsal) aspect (fig. 50 6), on the summit of which they 
form an obscure “ saddle.” The test is known only in one species 
(Jovellania Buchi., de Vern., sp.), and in this it is ornamented with 
transverse coarse annulations. 
I recognize, at present, the following species as comprised in the 
genus Jovellania^ viz. : — Orthoceras Murrayi, Billings, Orthoceras 
capitolinum, Safford^ (Ordovician of Xorth America), 0. ArcMacP and 
0. victor Barr. (Silurian of Bohemia), 0. triangulare., d’Arch. and 
de Yern. (Devonian of the Eifel), 0. Jovellani, de Yern. (Devonian 
of Spain), 0. Buchi, de Yern. (Devonian of France), and perhaps 
“ Gomphoceras ” Hesperis, Eichw. (Carboniferous of Russia). 
Remarhs. The “ triangulare-^TOMp ” of Kayser, referred to above, 
was constituted for the reception of Orthoc. Archiaci and 0. victor, 
Barr., and 0. Jovellani and 0. Buchi, de Yern., of the Spanish 
Devonian, besides other undescribed species. Y’ith reference to 
its systematic position, Kayser questions whether the “ triangular e- 
group ” can be correctly classified with Orthoceras ; and he observes 
that the thick and rayed siphuncle, and the unusually crowded septa 
of the species comprehended in it, vividly recall similar features in 
the large Cyrtocerata of the Eifel and of the Bohemian Etages 
E & G, such as lineatum, Goldfuss, and Icetificans and desolatum, 
Barrande ®. 
Dr. Kayser adds that the generic position of the forms included 
^ Lethiea Rossica, toI. i. p. 1270, pi. xlix ff. 4a-c & 8a-c. 
^ Geol. of Tennessee, 1869, p. 290, pi. iv. (G 3) ff. 1 a, 1 6 (excl. 1 c). I re- 
ferred this species above (p. 174) to the genus Actinoceras, but that reference I 
now believe to have been erroneous, and I take this opportunity of correcting 
it. The species figured by Safford (i. e. ff. 1 a, 1 V) agrees perfectly well (so 
far as one can judge by outline drawings only) with the forms I have included 
in Jovellania. 
^ Syst. Sil. de la Boheme, vol. ii. Texte iii. 1874, p. 102. 
^ Loc. cit. p. 104. Barrande admits, however, that this species may be only 
tlie young of 0. Archiaci. 
* Syst. Sil. de la Boheme, vol. ii. pi. cccclxviii. and pi. dxiii. 
