72 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 3 



4. Chaetoceros approximatus Gran and Angst 



5. costatus Pav. 



6. subsecundus (Grun.) Hust. 



7. Corethron hystrix CI. 



8. Dactyliosolen mediterraneus Perag. 



9. Ditylum brightvvellii (West) Grun. 



10. Lauderia borealis Gran 



11. Licmophora abbreviata Agardh 



12. species 



13. Nitzschia pungens var. atlantica CI. 



14. Rhizosolenia acuminata (Perag.) Gran 



15. alata f. indica (Perag.) Osten. 



16. bergonii Perag. 



17. imbricata var. shrubsolei (CI.) Schrod. 



18. species 



19. styliformis var. longispina Hust. 



20. Schroderella delicatula (Perag.) Pav. (ocean only) 



21. Stephanop}Tcis turris (Grev. and Arn.) Ralfs 



22. Surirella species 



23. Triceratium species 



The species of diatoms found in the Gulf are not notably different 

 from those found in the ocean outside the Gulf off Lower California 

 or particularly different from those found at La Jolla. 



Condition of Specimens 

 As customary with all phytoplankton collections studied at the 

 Scripps Institution, record was kept of cells in good condition and of 

 cells in poor condition. In 1936, the Gulf series was notable for the 

 relatively small number of cells in poor condition. Allen reported that 

 no catch of significant size showed as many as 10 per cent of the speci- 

 mens in poor condition. While the same statement cannot be made for 

 the 1937 series, in most cases the number of cells in poor condition was 

 low for the major catches. Half of the catches of over 10,000 cells 

 per liter had more than 10 per cent of the cells in poor condition, half 

 less than 10 per cent. One catch, taken south of Guaymas, with a total 

 of 3,300,500 cells had 1,029,000 in poor condition. The large catches 

 taken north of Angel de la Guardia Island all had fewer than 10 per 

 cent of the cells in poor condition. 



Summary and Conclusions 

 1. Seventy-three surface samples of phytoplankton were collected 

 between March 1 and April 4, 1937, by the Allan Hancock Expedition 



