Gephyrea 197 



moist but not wet, and additions of spent coffee grounds were made at 

 intervals of a month or so. Excessive moisture was corrected by leaving 

 the cover slightly raised. The culture has lived through the three 

 summer months without any attention, but was rather weak in the fall.* 



Class Gephyrea 



CULTURING LARVAE OF URECHIS CAUPO 



G. E. MacGinitie, California Institute of Technology 



THE larvae of the echiuroid, Urechis caupo, may be successfully 

 reared by the method given below. This method has also been used 

 to rear the larvae of the phoronid, Phoronopsis viridls, the polychaete, 

 Halosydna brevisetosa, the tectibranch mollusk, Tethys calijornicus, and 

 sand dollars and sea urchins. No doubt it will serve as a method for 

 rearing many others as yet untried. The following materials will be 

 required: Syracuse watch glasses; finger bowls with glass covers; sea- 

 water, preferably filtered not long before use; pipettes or medicine 

 droppers with the small end pulled out to % or % of its original opening; 

 at least two pipettes more finely drawn out with which to tap the animals 

 for eggs and sperm, and a diatom culture. 



COLLECTING THE ANIMALS 



Urechis caupo inhabits the salt water estuaries of the west coast from 

 San Diego northward. They build elongated U-shaped burrows with 

 two openings to the surface of the mud. These openings are on an 

 average about 30 inches apart, and the burrow itself is from 12 to 16 

 inches deep. Although the mud flats of estuaries are perforated with the 

 openings of burrows of a great variety of animals, each and every opening 

 in some way gives a clue to the underground inhabitant that made it. 



♦Editor's Note: Mr. Ralph W. Moltke of 106 Broadway, Peoria, Illinois, issues a small 

 bulletin on permanent-bed culture of Allolobophora [—Eisenia] foetida that he sells to 

 fishermen and to dealers in baits for fishing. It contains detailed practical instructions. 

 With his permission we summarize here the main features of his plan. 



1. Select a shady place in well-drained soil for a bed, say 3x6 feet. 



2. Dig out a foot or more of soil and fill with well rotted manure. 



3. Wet it down thoroughly and introduce the worms by distributing them over the 

 surface. 



4. Cover them with a sprinkling of dirt and allow them time to burrow. 



5. Add some pieces of hard stale bread soaked in water and cover these with dirt. 



6. Feed the worms once a week by spreading over the surface of the dirt corn meal, 

 old bread, or vegetable refuse from the kitchen, covering this with dirt each time and adding 

 a layer of straw or gunny-sacking to retain the moisture. Sprinkle the bed with water 

 whenever it shows signs of getting dry. 



7. Remove worms for use by turning over surface layer with a hand digging-fork, 

 digging in a new place each time. 



J. G. N. 



