Hydroids of Laguna Beach 



PROF. A. M. BEAN 

 PACIFIC UNIVERSITY, FOREST GROVE, OREGON 



The Identification of the hydroids included in this Hst was under- 

 taken while making a general collection of the marine forms of the 

 Laguna Beach region. The specimens were taken mostly from 

 the miscellaneous shore collections, and there Is no claim to exhaus- 

 tiveness. They were, however, examined as fresh material, and 

 nearly always with the living polyp still present. There was abun- 

 dant promise of opportunity for the study of ecological and develop- 

 mental problems, of which I was unable at that time to take 

 advantage. 



The region covered included a strip of shore line of about two 

 miles In extent. Part of this is sandy beach which after a heavy 

 tide would often be covered by the laminae and holdfasts of 

 Macrocystis and other kelps, to which hydroids were generally 

 attached. The remainder of the shore was rocky and of a re- 

 markably varied conformation, including tidepools, deep channels, 

 rock tables, mussel beds, and short stretches of sand and pebbly 

 beach. Scarcely any attempt was made at dredging, and the shore 

 itself was by no means completely searched. 



GYMNOBLASTEA 

 Family PENNARIID^ 

 Tiibtdaria sp. 

 This single representative of the Gymnoblastea more nearly cor- 

 responds to the T. mar'uui described by Torrey, '02. It is, however, 

 much smaller, the erect branches being scarcely ever as much as 15 

 mm. In length. Instead of 30-50 mm. The proximal tentacles are 

 28 and 29 In number, instead of 22-26, described for T. marina. 

 There is very little appearance of annulatlon of the stem, and no 

 evidence of the "stem increasing in diameter distally." The hab- 

 itat is also different. T. marina is given as growing "between tides 

 on the lee side of rocks exposed to the breakers of the open sea." 

 The tubularian in question, however, was found only clustered in 



