prised at the number and variety of mollusks which will be seen crawling 

 about, along with other animals (notably Foraminifcra). The water in the 

 dish should be gently swirled around so that the material settles near the 

 center. As the oxygen content of the sea water is decreased, many of the 

 mollusks, including some of the small clams, will crawl to the edge of the 

 dish and cluster at the surface. This is the best means of separating most 

 of the live animals from the sand grains and detritus at the center of the 

 dish, but there are always some which do not crawl to the edge. Those at 

 the edge may be picked up with a small brush and placed in one vial of 

 alcohol and the remaining material may be put in another. In this way 

 part of the mollusk sample is already separated without sorting. A portion 

 of the alga from which the sample came should, ideally, be pressed so that 

 it can be identified by an algologist. In this way more data will accumulate 

 on the degree of specificity of mollusks to algae. 



If little time is available in the field, as is usually the case, and if the 

 collector cannot take a microscope with him, algae can be collected in jars 

 to be pulled apart and washed with fresh water later, for the mollusks will 

 stay alive for a number of hours. The residue from the bucket can be put 

 directly into vials of alcohol. A few minutes spent gathering algae will 

 often result in many hours of sorting afterwards with a microscope. 



The WTiter has collected species of the following genera in great 

 abundance in the Bahama Islands, using this technique: Caecum, Rissoella, 

 Amphithalamus, Assiminea, Lasaea, Musculus. The following are scarcer: 

 Schismope, Pseudostomatella, Tricolia, Alvania, Litiopa, Triphora, Seila, 

 Rissoina, Psarostola, Mitrella, Persicula, Marginellopsis, Odostomia, Pedipes, 

 Carditopsis, and Papyridea. — Robert Robertson, Museum of Comparative 

 Zoology, Harvard University 



Collecting in Seaweed Holdfasts. Seaweed holdfasts are a good collect- 

 ing ground for marine shells that nestle or hide in the twisted mazes of 

 kelp roots. Those that are torn loose from their rocky moorings and washed 

 ashore after heavy storms often contain species that are rarely found, even 

 by dredging. 



On a number of different occasions when searching the offshore beds 

 of the giant kelp (Macrocystis) in Monterey and Carmel bays of California 

 with a rowboat, the attempt has been made to pull up the kelp by the 

 roots. This is often impossible if the roots are well anchored as the stems 

 usually break first. Sometimes, however, the attempt has been successful 

 and the holdfast brought to the surface, often with a heavy boulder or slab 

 of rock on which the kelp roots grew. In such instances the reward in 

 shells collected from their roots and their attachment is usually worth much 

 unsuccessful effort. 



Once, while hopefully hauling on kelp stems to break one of the roots 

 from its fastenings, one finally gave way and was brought to the surface 

 from a depth of about 10 fathoms. It proved to be an unusually large and 

 complete one, with a widespread tangle of roots nearly 4 feet in diameter 

 and 2 or 3 feet thick. Along with the roots came several slabs and many 



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