Molluscoida at Laguna Beach 



ENTOPROCTAN BRYOZOANS 



Myosoma spinosa Robertson. These were obtained in considerable numbers from 

 the surfaces of wavy top shells, Astraea undosa Wood. These shells were dredged 

 in from ten to fifteen fathoms of water just off shore. 



Barentsia gracilis Hincks. These were determined for us by Dr. Robertson. 

 Specimens have been collected every summer for the last few years. Thev occur 

 under stones at low tide. They have also been found in abundance on the under sides 

 of the worm cases of Sabellaria californica and under rock ledges. In spite of their 

 small size these little "bobbing heads" are quite evident in extensive areas. 



FRESH WATER BRYOZOANS NEAR LAGUNA 



Pining the summer of 1915 a number of specimens of fresh water bryozoans were 

 collected on submerged leaves in the medium-sized lake, six miles inland from 

 Laguna Beach. In the summer of 1917 no bryozoans were found in this lake, but 

 some were found at the south end of the more northern lake and at the east end of 

 the largest lake. Some of these were determined by Dr. Robertson as Plumatella 

 repens L. 



ECTOPROCTAN BRYOZOA 



The following have been determined from the papers of Robertson: 

 NON-INCRUSTING FORMS 

 Aeteid.^e 



Aetea anguina Linn. Found on brown alga;. 



EUCRATIID/E 



Eucratea chelata Linn. Found on a dredged decorator crab. 

 Cellularid.'e 



Menipea occidentalis Trask. 



M.n. catalinensis Rob. From kelp holdfasts. Some on decorator crab. 



Scrupo cell aria californica Trask. 



S. variant Hincks. Kelp holdfasts. 



S. diegensis Rob. Under rocks, low tide. 



BlCELLARIIDTE 



liugula neritina Linn. Common under rocks. Also on piles at Balboa Bay. 

 Bugula Sp. Apparently not given by Robertson. 

 Cellariid^e 



Cellaria mandibulata Hincks. Abundant along shore. 

 Vesiculariid^ 



/ niatina dit liotoma Yer. Masses of what appeared to be this species occurred 

 under rocks at Laguna and ;iKm on the piles at Ballma Ba\. This nften 

 swarms with mnnv smrrtt p\ rnngniiids. 



INCRUSTING BRYOZOA 



Membraniporid^ 



Membranipora tehuelcha d'Orbigny. Abundant on sea weeds, often large masses. 

 M. membranacea Linn. On large flat algas. 

 Membranipora sp. ? 



