ID Keys
*Images in development

Lyonsiidae, Verticordiidae & Poromyidae (500 - 5000m)

Oblong, posterior obliquely truncate, posterior area set off by an oblique ridge, posterior area with radial riblets, anterior area with weak oblique ridges, overall with microscopic spines in radial rows.
Allogramma formosa
Subcircular to quadrate shells with beaks at midline or subquadrate shells with beaks in front of midline, many with radial threads and or rows of pustules
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Subcircular shell with coiled beaks and 13-16 acute carinate radial ribs.
Spinosipella acuticostata
Subovate to quadrate shells lacking prominent radial ribs
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Quadrate-polygonal solid shell with a median oblique carina and a lower carina on either side dividing shell into 4 regions
Halicardia flexuosa
Shell not massive or divided into regions by carinae
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Shell triangular to subquadrate overall with microscopic pustules
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Shell triangular, beaks at midline, pustules arranged in rows
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Shell triangular, beaks at midline, pustules arranged in rows
Verticordia triangularis
Shell obliquely oval or subquadrate
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Shell subquadrate, posterior truncate, weak radial lines present
Lyonsiella abyssicola
Shell subovate, posterior rounded, radial lines absent, pustules large
Lyonsiella subquadrata
Posterior dorsal margin sloping creating a broadly rounded anterior margin and somewhat extended ventrally, radial lines dense up to 50 in largest
Policordia densicostata
Posterior dorsal margin straight creating a narrowly rounded anterior profile.

Similar shells from the subarctic and arctic are referred to
Policordia jeffreysi. Policordia atlantica has a sculpture of sunken grooves rather than raised threads and is not recorded from the NE Atlantic.
Policordia gemma