668 GREENE. [Vol. XV. 



It is my purpose in this paper to present the distribution, 

 structure, and development of the phosphorescent organs in 

 Forichthys, together with their surface relations to the lateral- 

 line system of sense organs.' In the future I hope to follow 

 with a second paper on the morphology of the lateral-line 

 system, work now partially completed. 



The results presented in this paper were obtained chiefly 

 from the study* of Forichthys notatus Girard. But I have 

 also some material from Forichthys nautopedium Jordan and 

 a new species of Forichthys kindly furnished me by Frof. 

 C. H. Gilbert. 



Forichthys notatus is found abundantly along the Facific 

 coast from Sitka to Fanama. It is taken in early spring and 

 summer at tide water where it comes to spawn. The eggs are 

 cemented in a single layer to the under surfaces of stones, and, 

 as the male remains with the brood until the young become 

 free-swimming (when they are about one inch in length), it 

 is comparatively easy to secure adults together with young. 

 Adults are also taken in large numbers in the trawls on the 

 fishing banks north of San Francisco in spring and summer. 

 In winter they are very scarce on the banks. 



In a surface view, the phosphorescent organs appear as 

 bright silvery spots distributed in lines or rows over the surface 

 of the body of the fish. The average number of organs is about 

 350 on each side of the fish, 700 organs in all. Of these, 275 on 

 either side are located in eight lines on the ventral and ventro- 

 lateral surface of the body. In this region the rows are very 

 conspicuous (PI. XXXVIII, Figs, i and 2), but more obscure 



1 The material for this study was collected and the work begun at the Hopkins 

 Seaside Laboratory, Pacific Grove, Cal., in the summers of 1892 and 1S94. I am 

 deeply indebted to the directors, Dr. O. P. Jenkins and Dr. C. H. Gilbert, for the 

 privileges of the laboratory and for advice and encouragement. I wish also to 

 express my indebtedness to Dr. C. O. Whitman for the privileges of a table at 

 the Marine Biological Station, Woods HoU, Mass., during the summers of 1S96 

 and 1S97 ; also to thank the members of the instructing corps for suggestive 

 criticism and advice. Miss Clapp has kindly allowed me to e.xamine her manu- 

 script on the Lateral-Line System of Opsanus tau, and has criticised my manuscript, 

 as well as given me many suggestions as to methods of making preparations. And, 

 finally, I am especially indebted to my wife, whose invaluable criticism and enthu- 

 siastic interest have been my constant support. 



