Table 1 List of gymnolaemate bryozoans investigated herein

Ctenostomata

 Alcyonidioidea

Alcyonidium sp.

15

13

+/−

Flustrellidra hispida

27

25

+

tentacle sheath ring

 Arachnidioidea

Nolella dilatata

17

17

–

no ‘gap’

 Paludicelloidea

Paludicella articulata

18

16

–

highly complex

 Victorelloidea

Victorella pavida

8

6

–

 Walkerioidea

Walkeria uva

8

6

–

 Vesicularoidea

Zoobotryon verticillatum

8

6

–

 Vesicularoidea

Amathia semiconvoluta

8

6

–

Cheilostomata

 Inovicellata

Aetea anguina

11

9

+/−

 Malacostega

Membranipora membranacea

17

15

–

 Malacostega

Electra pilosa

13

11

–

 Buguloidea

Bugula purpurotincta

15

13

–

 Buguloidea

Bicellariella ciliata

15

13

+

visc. nerve, cardiac nerve ring

Scrupocellaria scruposa

12

10

+

 Cellarioidea

Cellaria fistulosa

14

12

–

pore-complex

 Hippothoomorpha

Chorizopora brongniartii

12

10

–

 Cribrimorpha

Cribrilina annulata

13

11

–

visc. nerve, cardiac nerve ring

 Lepraliomorpha

Schizoporella sp.

13

11

–

 Lepraliomorpha

Cryptosula pallasiana

16

14

+

 Lepraliomorpha

Lanceopora sp.

17

15

–

 Umbonulomorpha

Reptadeonella violacea

15

13

–