ID Keys
*Images in development


Elliptical shell, gaping widely along the entire ventral margin. Sculpture of dense divaricating riblets (Free-living)
Galeomma turtoni
Shells not gaping, sculpture primarily commarginal
Go to #2
RV with single anterior and posterior radiating "lateral" flanges widely separated by ligament inserted into the umbonal cavity, no obvious resilifer. Left valve with lateral teeth as extensions of the dorsal margins
Go to #3
Hinge not of this arrangement
Go to #6
Shell transversely subovate, posterior subtruncate not markedly narrower than anterior
Go to #4
Shell obliquely subovate, posterior narrowly rounded, markedly narrower than anterior
Go to #5
RV teeth strong diverging ca. 100° (shelf)
Kurtiella bidentata
RV teeth proportionately small diverging ca. 90° (upper slope)
Kurtiella pellucida
RV teeth diverging ca. 110° (upper slope, shelf edge)
Kurtiella tumidula
RV teeth diverging ca. 90° (upper slope, shelf edge)
Kurtiella ovata
External macro-sculpture other than incremental lines
Go to #7
External sculpture of incremental commarginal lines only
Go to #10
Radial elements present in shell or periostracum
Go to #8
Punctate or anastmosing commarginal elements present
Go to #9
Radial ribbing evident at margins and internally
Bornia sebetia
Periostracum drawn out into radial rows of short bristles
Pseudopythina macandrewi
Shell punctate (attached to Upogebia)
Lepton squamosum
Shell with anastamosing commarginal ridges
Coracuta obliquata
Ligament set in a posterior oblique resilifer or on resilial ridge, posterior lateral teeth absent
Go to #11
Ligament on a median or posterior resilifer, posterior lateral teeth present
Go to #19
Outline subelliptical, L>H, beaks towards the posterior, ligament on a raised resilial ridge resembling a posterior tooth
Go to #12
Outline subquadrate to subovate, beaks at or behind the midline, ligament on a shallow sunken resilifer
Go to #13
Posterior dorsal margin high, with Echinocardium
Tellimya ferruginosa
Posterior dorsal margin sloping, with Brissopsis
Tellimya tenella
Outline subquadrate, expanded anteriorly, anterior broadly truncate with Leptosynapta spp.
Devonia perrieri
Outline roundly subovate, oblong or subovate-trigonal, beaks close to the midline
Go to #14
Outline oblong, equilateral, surface obscured by heavy brown deposit, with Phascolion strombi inside Turritella and Apporhais shells
Montacuta phascolionis
Outline inequilateral, beaks behind or just behind midline
Go to #15
Outline obliquely oval to roundly subovate beaks behind midline
Go to #16
Outline subovate trigonal rather angular
Go to #18
Obliquely oval, radially striated, attached to spines of Spatangus and Echinocardium
Montacuta substriata
Roundly subovate
Go to #17
Swollen anteriorly, high at anterior dorsal margin, abyssal attached to Pourtalesia
Syssitomya pourtalesiana
Anterior a little broader than posterior, sloping away at anterior dorsal margin, abyssal attached to Aeropsis
Kelliola symmetros
Anterior dorsal margin concave, microscopically radially striated
Scacchia tenera
Anterior dorsal margin sloping, lacking microsculpture
Scacchia sp.
[Taxon under review]  
Ligament on a shallow depression in the hinge plate beneath the beaks
Go to #20
Ligament in a deep depression interrupting the hinge plate behind the cardinal teeth
Go to #21
Hinge with a hooked cardinal in LV and corresponding socket in RV, subcircular shell with fine regular commarginal ridges
Neolepton sulcatulum
Hinge with simple cardinal teeth, obliquely oval shell not exceeding 1.5mm
Altenaeum dawsoni
A single discreet cardinal in each valve
Go to #22
A single discreet cardinal in RV only
Go to #23
Outline rounded subquadrate, cardinals projecting, microscopic pits present on teleoconch
Hemilepton nitidum
Outline subcircular, not exceeding 1.6mm, cardinals low, attached to the tanaid Apseudes
Arculus sykesi
RV with strong anterior and posterior laterals with sockets into which fit the LV laterals, associated with sipunculans
Epilepton clarkiae
Lateral teeth poorly developed, LV as marginal extensions
Go to #24
Obliquely oval, anterior dorsal sloping, bathyal associated with glass sponges
Draculamya porobranchiata
Obliquely ovoid , anterior dorsal raised, anterior expanded
Kelliopsis jozinae