UNIVERSITY OF CALIFORNIA PUBLICATIONS 



IN 



ZOOLOGY 



Vol. 13, No. 2, pp. 21-38 April 14, 1914 



A STUDY OF THE OCCURRENCE AND MANNER 



OF DISTRIBUTION OF THE CTENOPHORA 



OF THE SAN DIEOO REGION 



BY 



CALVIX O. ESTERLY 

 (Contribution from the Scripps Institution for Biological Research) 



The basis of this paper is found in the results obtained from an 

 enumeration of the ctenophores in 274 surface hauls, and in 816 sub- 

 surface collections with closing- nets made at the Scripps Institution 

 for Biological Research. They were made between June 16. 1908, and 

 April 17, 1913. The complete data for all hauls is to be published 

 in book form by the Institution and I have given here only the num- 

 bers for the successful hauls and the numbers of animals obtained in 

 them. It is to be understood that any other collections made within 

 the periods named above were unsuccessful so far as the Ctenophora 

 are concerned. 



The general terms and explanations used in Michael's paper (1911) 

 and in mine (Esterly, 1912) are applicable here. In addition it 

 should be stated that, beginning with haul 2289, all surface collecting 

 has been done with a net of smaller filtering capacity than the 000 

 silk net. As can be seen from table 1, some of the hauls with the 

 former net (spoken of as the 000 C) obtained Pleurobrachia in excep- 

 tionally large numbers and the collections would have been larger 

 if the 000 silk net had been used under the same conditions. 



Ctenophores were present in 79 of the surface hauls, and 70 of 

 the successful hauls contained specimens of Pleurohrachia hacJtei; that 

 is, 25 per cent of all hauls contained this ctenophore. Euplokamis 

 calif orniensis (probably Hormipkora palmata: Bigelow, 1912, p. 381) 

 appeared in fifteen hauls, and Beroe forskali in five. It is interesting 



