242 CEYLON PEARL OYSTER REPORT. 



Calanus vulgaris (Dana). 



The most generally distributed of any species throughout the route traversed, 

 occurring at 70 stations, from the Red Sea southwards. 



Calanus robustior, Giesbr. 



Only once taken, at Station 21, off Minikoi. in the Indian Ocean; previously 

 known from the Atlantic and Pacific Oceans. 



Eucalanus attenuatus (Dana). 



Occurred plentifully at 18 stations, -from the lied Sea southwards through the 

 Indian Ocean to Ceylon. 



Eucalanus pileatus, Giesbr. 



Taken at 4 stations only, twice in the Red Sea and twice in the Indian Ocean, 

 which adds to its hitherto known distribution in the Atlantic and Pacific. 



Eucalanus crassus, GlESBK. 



Occurred once in the Red Sea and at 4 stations round Ceylon ; previously reported 

 from the Indian Ocean. 



Eucalanus subcrassus, Giesbr. 

 Occurred at 27 stations ; twice in the Red Sea, and throughout the Indian Ocean. 



Eucalanus subtenuis, Giesbr, 

 A few specimens were found from 9 stations, all in the sea roimd Ceylon. 



Eucalanus nionaclius, Giesbr. 



A rare species hitherto known only from the Mediterranean. Specimens were 

 found, off Ceylon, at 2 stations, thus extending its known range to the Indian 

 Ocean. 



Ehiucalanus cornutus (Dana). 



Reported from 10 stations, all in the Indian Ocean. Previously known from the 

 Mediterranean, the Atlantic, and the Pacific. 



Rhincalanus nasutus, Giesbr. 

 Similar in distribution to the last species. Occurred at 8 stations in the collection. 



Mecynocera clausi, I. C. Thompson. 



Found at 27 stations, extending from the Red Sea throughout the Indian Ocean, 

 the latter being an addition to its hitherto known distribution. 



