1911] Kofoid: The Genus Gonijaulax. 189 



low waters and of the invertebrates such as the holothurians, 

 annelids, sipunculids, and some of the moUnsks [see Torrey 

 (1902)]. It is east upon the sands along shore by the breakers 

 and its decay there, together with that of the animals killed by its 

 abundance, causes a stench which suggests that of the Nile which 

 in Hebrew writings is recorded as having turned to blood. It is 

 not improbable that the phosphorescence and red Avater reported 

 by Darwin (1871) off the coast of South America and by Streets 

 (1878) in the Gulf of California, was caused by this species or 

 some related dinoflagellate. 



Present Status • 



Although widely distributed and at times abundantly repre- 

 sented in the plankton, this genus has remained in a state of 

 imperfect definition and has been a great source of uncertainty 

 and a cause of oft recurring confusion in the matter of its char- 

 acters and its limits. Very few of the species assigned to it, 

 even in recent years, have been accurately defined in the matter 

 of their skeletal morphology, and a number of older species of the 

 genus have been variously interpreted by later writers with the 

 result that it has become increasingly difficult to determine with 

 what species an author is dealing, unless his work is accompanied 

 by figures and in some cases not even these relieve the confusion 

 which reigns in this genus. Another and very fundamental rea- 

 son for this confusion lies in the fact that a wide range of 

 material is often necessary to determine the limits of variation 

 within the species of the genus. This wide range in variation 

 coupled with the very dissimilar appearances which even the 

 same individual may present from different points of view, make 

 the interpretation of the older literature, and some of the more 

 recent, exceedingly difficult, and usually force the investigator 

 to a re-examination of pertinent material before he can come to 

 any conclusion that does not rest all too much upon conjecture. 



B. MATERIAL 



This paper is based primarily upon the examination of the 

 plankton collected off the coast of southern California by the San 



