Notes on Sponges at Laguna Beach 



W. L. GROW 



During two summers Mr. Grow collected and studied sponges at Laguna Beach. 

 We have not been able to get any of the local forms satisfactorily determined, and 

 the notes here given are simply suggestions. We shall be glad to turn over an 

 abundance of material to any one who wishes to work on the group. 



At least three kinds of simple calcareous sponges were found under rocks and 

 on kelp holdfasts. 



Leucosolenia sp.? is found at times under rocks at low tide. The sponge is about 

 10 to 12 mm high and narrower at the base, white, slender, not very abundant. 



At least two species of Sycon or Grantia were found under stones and on hold- 

 fasts. Those from deeper water have longer spicules. 



The most conspicuous sponge at Laguna is found in masses under rock ledges. 

 It is often quite large and irregular in outline. It is sometimes divided into many 

 partially separate colonies and again it may occur in a smooth mass. It is pure white. 

 Possibly it belongs to the genus Petrostoma. In its cavities several animals often 

 retreat, small crabs of the genus Pachygrapsis and young and adults of the crab 

 Pachycheles rudis Stimp. and the isopod Cirolana harfordi var. spongicola Staf. 



A species of Clathtina occurs at Laguna Beach now and then. During some win- 

 ters this stalked white, mushroom-like species is found among tufts of Bryozoa. 



The so-called sulphur sponge is common under stones and rock ledges. There 

 is no differentiation into individuals, the oscula are scattered over the surface, which 

 mav be verv irregular. Great masses of these yellow sponges are often found. The 

 onlv animal associated with them seems to be the limpet Tylodina fungtna Gab. 



Pink encrusting sponge. Found on shells, seaweed, etc. Pink-white, smooth, few 

 openings evident. Calcareous spicules triaxons and monaxons. It is rather thin. 



White encrusting sponge (I) White, fused at the base, but with distinct, erect 

 individuals each with osculum. Often covered with Bryozoa. Triaxon spicules and 

 spongin fibers present. Under ledges of rock. 



White encrusting sponge (II). Soft white, but tenaceous. Peels off from shells 

 and twigs. Has only triaxon spicules. Found on rock surfaces, seaweed, kelp hold- 

 fasts. 



Red sponge. Bright red, feels spongy. Encrusts a base and sends out tufts which 

 fuse. Triaxon spicules. Spongin fibers, rather broad cavities. On seaweeds and 

 under rocks. 



Yellow sponge. From a yellow to an ocher. Never the color or texture of the 

 sulphur sponge. Semi-encrusting with some erect irregular portions which may fuse 

 again with the parent mass. Parts may wind and twist among bryozoan masses. 

 Monaxon spicules, granular structure. Surfaces of rocks, rock ledges and seaweeds. 



White dermal sponge. Soft spongy, greyish white. Fibers or strands easily seen 

 by the naked eye. Grows under ledges. Composed of spongin fibers. Some dry bits 

 cast up on the shore seem to be of as good quality as a first class bath sponge. 



