78 



description of C. carinatus were found with the former in St. 

 John's Bayou, although in less numbers. A third species from 

 the plankton, with extremely attenuated abdomen, differs mate- 

 rially from any descriptions of species with which the writer is 

 acquainted. The genus is rather well provided with species, and 

 until all descriptions are available, so that full comparisons can 

 be made, the form has been retained for further study. 



SUMMARY OF THE FOREGOING SPECIES. 



St. John's Calcasieu 

 Plankton Bayou Pass 



Calanus minor ^ 



Eucalanus sp X 



Centropages typicus X 



Centropages furcatus X X 



Centropages sp X 



Eurytemora affinis X 



Labidocera sp X 



Acartia gracilis X X X 



Acartia tonsa X 



Tortanus sp X 



Githona similis X X 



Miracia efferata X 



Ameira sp X X 



Laophonte mississippiensis (?) X 



Oncaea venusta X 



Corycaeus elongatus X X 



Corycaeus carinatus X X 



Corycaeus sp X 



Species 12 6 7 



The writer begs to offer his best thanks to Prof. H. A. Morgan 

 for many courtesies extended him during his stay at the Station. 



