STUDIES ON MARINE BRYOZOA, III. WOODS HOLE REGION BRYOZOA ASSOCIATED WITH ALGAE

¹ College of New Rochelle, New Rochelle, N. Y.
² Dartmouth College, Hanover, N. H.

1. A total of 30 bryozoan species was reported from 37 species of marine algae.

2. Five bryozoan species were reported from three species of green algae, 26 bryozoan species from 11 species of brown algae, and 27 bryozoan species from 23 species of red algae.

3. Phyllophora membranifolia yielded the greatest number of bryozoan species (23), Chondrus crispus and Laminaria Agardhii each yielded 20, Phyllophora Brodiaei, 15, and Cystoclonium purpureum cirrhosum yielded 11 bryozoan species.

4. Each of the three commonest bryozoa, Aetea sica, Bowerbankia gracilis and Crisia eburnea, was found on 18 algal species.

5. Each of the two next commonest bryozoa, Electra pilosa and Hippothoa hyalina, occurred on 17 red and brown algal species.

6. Bugula turrita, the next most common form, was found on 16 algal species.

7. Crisia eburnea and Hippothoa hyalina were common on over half the red algal species examined.

8. Some bryozoa seemed to grow most frequently and abundantly on certain algal species, namely:

a. Alcyonidium polyoum on Chondrus crispus, Phyllophora Brodiaei, and P. membranifolia

b. Bowerbankia gracilis on Ascophyllum nodosum, Chondrus crispus, Fucus vesiculosus, F. vesiculosus spiralis, Phyllophora Brodiaei and P. membranifolia

c. Crisia eburnea on Chondrus crispus, Phyllophora Brodiaei and P. membranifolia

d. Electra pilosa on Laminaria Agardhii and Rhodymenia palmata

e. Flustrella hispida on Ascophyllum nodosum.

9. To the 84 known Woods Hole region bryozoan species can be added three more : Aetea sica, Cellepora dichotoma and Scruparia ambigua. It is quite possible that some of the previously reported Aetea anguina and Cellepora americana material may have included Aetea sica and Cellepora dichotoma, respectively.

10. Algal collections from New Rochelle, N. Y., yielded some of the same bryozoan species as are found in Woods Hole, namely : Alcyonidium polyoum, Bowerbankia imbricata, Cryptosula pallasiana, Electra hastingsae, Membranipora lacroixii(?), and Pedicellina cernua.

11. Algal collections from Rye, N. H., yielded some of the same bryozoa as are found at Woods Hole, namely: Callopora aurita, Cribrilina annulata, Cribrilina punctata, Crisia eburnea, Electra pilosa, Hippothoa hyalina and also a form, Lichenopora hispida, which did not occur at Woods Hole.

12. Twenty-six of the thirty bryozoan species were carefully illustrated.

13. Tentacle number counts were made for 15 species.

14. Three bryozoan species were collected, observed, or known to be in the larva-producing stage on algae in late June; seven species in July; ten in August; two in September. These were chance observations and the number of species would have been greater if more exhaustive collections over a greater number of months could have been made.