SUB-ORDER B RHIPIDOGLOSSA 445 
Bellerophon, Montf. (Waagenia, de Kon.), (Fig. 806). Shell globose or discoidal, 
more or less convolute, and narrowly umbilicate on both sides. Aperture sub-circular 
or oval, with a deep median 
sinus; slit-band either dis- 
tinct or replaced by a keel, 
sometimes absent. Outer 


Fic. 807. 
x. S06. ae 
Fra. 806 Bellerophon (Euphemus) Urii, 
Bellerophon bicwrenus, Leveillé. Carboniferous ; Tournay, Flem. Carboniferous ; Edin- 
Belgium. burg. 
lip sharp, columellar edge often with callus. External surface marked only by 
growth-lines. Silurian to Permian; maximum in 
Carboniferous. 
Sub-genera: Bucania, Hall. Silurian and Devonian. 
Warthia, Mogulia, Waagen. Carboniferous. 
Euphemus, M‘Coy (Fig. 807). Like Bellerophon, 
but the inner whorls, and a part of the last, spirally 
striated. Carboniferous. 
Fic. 808. Salpingostoma, Roem. Shell widely unbilicate, 
Cyrtolites ornatus, Conrad. 4, Speci: the aperture suddenly becoming greatly dilated. 
men viewed from one side, from Ordo- Whorls traversed along the middle by a slit closed 
vician of Boonville, New York (after ; 5 ; M : 
F. Roemer). B, Anterioraspect ofspeci- anteriorly and posteriorly. Silurian and Devonian. 
te ae et Cineinnat, Trematonotus, Hall. Like the last, but the slit- 
band replaced by a row of perforations. Silurian. 
Cyrtolites, Conrad (Fig. 808). Shell widely umbilicate, keeled, without slit, and 
with strong transverse ribs) Cambrian to Carboniferous. 

Family 4. Fissurellidae. Risso. 
Shell symmetrical, cap- or limpet-shaped, non-nacreous, without operculum. Apex erect 
or pointing backward, often recurved, perforated. Anterior margin often with a fissure ; 
young shell with a spiral nucleus. Marine; shore forms. Carboniferous to Recent. 
Of the three sub-families into which this group is divided, the Fisswrellinae are 
known only in the recent fauna. F%sswrellidinae occur in the Pliocene ; 
all the earlier forms are Emarginulinae. 
Fissurella, Brug. Shell conical, oval, with an oval apical orifice 
bounded inside by an entire callus. Recent. The numerous fossil 
species referred to this genus belong to Fissuridea. 
Fissurellidea, VOrb.; Pupillaea, Gray ; Megatebennus, Lucapinella, 
Pilsbry ; Macroschisma, Swains. These are all recent genera, with 
the apical orifice very large. 
Lucapina, Gray. Like Fisswrella, but with large apical orifice Fic. 809. 
and finely crenate periphery. Pliocene and Recent. _Fissuridea Italica, 
Fissuridea, Swains. (Glyphis, Cpr.; Fissurella, auct.), (Fig. 809). Got" ieee: 
Shell conical, oval, with apex in advance of the middle, giving place 
to a perforation which is bounded inside by a posteriorly truncate callus. Carbon- 
iferous (?) to Recent ; very abundant in the Tertiary. 

