1869.J Contribution to our knowledge of Pelagic Mollusca. 263 



5. Cleodora cuspidata, 



6. Ouvieria oryza, 



7. Spirialis trochiformis, 



8. S. tmcinata (?) 



I agree with Kang in thinking that Ouvieria rosea is an immature 

 form of Guv. collummella, and I also think Ouvieria oryza (Benson) 

 is a still younger form. I have repeatedly taken Guv. rosea and 

 Cuvieria oryza with the apex entire, as well as fractured, and of all 

 sizes. The three forms are doubtless one and the same shell. 

 To the Southern Ocean belong — 



1. Balantium australe, 



2. _Z?. recurvum (?). 



The remaining seventeen (or fifteen, if we exclude Guv. coll. and 

 Cuv. rosea) are common to the Atlantic and Indian Oceans. 

 As regards their habits the table shows that — 

 12 species are strictly nocturnal, 



7 j, are crepuscular and nocturnal, 

 12 „ are indifferent to solar influence. 

 Observations are, however, not sufficient yet to afford proper expla- 

 nation of much that relates to the habits and geographical distribution 

 of these interesting little creatures. Time alone can accumulate that 

 number of well-ascertained facts which is much required. There are 

 many intelligent and some enthusiastic workers in Mr. Green's em- 

 ploy, and if men so interested as Captain Edward Jones, and Mr. 

 Salier of the " Superb" to whose assistance I am greatly indebted, 

 would from time to time publish the results of their" observations, and 

 so stimulate others to varied and continuous experiments, uncertainty 

 regarding these animals would soon be dispelled. 



Diagrams were framed, showing the undulations of the temperature 

 of the air, and of the surface temperature of the sea, as registered 

 during two outward voyages round the Cape of Grood Hope. On the 

 first occasion, the Cape was rounded during the month of December or 

 at midsummer in that region. On the second, it was passed in June 

 or in the winter season. On both occasions, the observations were 

 made at noon ; and as the principal results of these I may, in con- 

 nexion with the object of this paper mention, that from about the 

 25th degree of South Latitude to the Equator in the Indian Ocean, the 



