A DELTA intkey to the Pyrgomatidae is currently being developed; an abbreviated version can be downloaded here. Definitions, descriptions, and illustrations of the characters and character states will be uploaded soon. This key uses the standard DELTA format; to download the software needed to view the key, please go to the DELTA website .


I've also prepared a separate identification key that's very handy for identifying pyrgomatines to the genus level....


Key to the genera within the Subfamily Pyrgomatinae


1 (0)     Basis membranous; in sponges  -- Pyrgopsella (Tribe Pyrgopsellini)

            Basis calcareous – 2

2 (1)     Wall 4-plated – 3

            Wall single-plated – 7

3 (2)     Opercular valves essentially balanoid – 4

            Opercular valves modified, tergal spur long  and prominent – Hiroa

4 (3)     Opercular valves separable – 5

            Opercular valves inseparable – 6

5 (4)     Adductor ridge  of scutum when present extending only slightly below basal margin; wall lacking longitudinal septa -- Cantellius

            Adductor ridge of scutum  extending well beyond basal margin; basal margin of wall with longitudinal septa – Arossella

6 (4)     Adductor ridge of scutum when present not extending below basal margin; tergal spur small – Creusia

            Adductor ridge of scutum extending below basal margin of the scutum; tergal spur moderate – Galkinia

7 (2)     Opercular valves separable – 8

            Opercular valves inseparable – 12

8 (7)     Scutum width greater than height; tergum triangular/pyramidal;  basis lacking atria – 9

            Scutum height greater than width; tergum sagittate; basis with atria – 11

9 (8)     Inhabits Millepora and other hydrocorals – Wanella

            Inhabits scleractinian corals (mostly) and stylasterines (rarely) – 10

10 (9)    Small tergal spur present; sheath adpressed and covers ~1/2 height of wall – Trevathana

             No tergal spur but with large spur tooth; sheath with slight free margin extending almost to basal margin – Savignium

11 (8)    Wall margin entire, not lobate – Pyrgoma

             Wall margin deeply lobate ( resembles ‘a torus suspended on flying butresses’) – Neopyrgoma (this assumes that Neopyrgoma has inseparable valves shaped similar to Pyrgoma – but genus is only known from 1 damaged specimen!)

12 (7)     Wall protean in outline; orifice minute – Hoekia and allied genera (Tribe Hoekiini)

              Wall uniform in outline; orifice  normal-sized  – 13

13 (12)    Opercular valves width greater than height, tergal spur highly reduced, walls with low broad ridges on external surface but lacking tall pillars – Neotrevathana

               Opercular valves delicate, width greater than height; tergum with long & narrow spur; wall with rows of tall pillars on external surface – Cionophora

               Opercular valves massive & stout, height greater than width; walls without rows of tall pillars on external surface – 14

14 (13)     Tergal spur absent; adductor ridge extends a moderate distance beyond the basal margin of the scutum; sheath extending almost to basal margin; wall bilamellar and tubiferous (due to longitudinal septa connecting 2 lamina) – Nobia

                Tergal spur present; adductor ridge extends well beyond basal margin of the scutum; sheath occupies ~1/2 of the inner wall; wall bilamellar and septate but non-tubiferous in adult (tubes secondarily filled with calcium carbonate) - Darwiniella

Pyrgomatidae homepage