119 



to such conditions of life as kindred animals would be now ; but I think 

 we should be cautious in forming any positive conclusions on this subject, 

 as the most of the animals are so different from any we know. Besides, 

 each species is subject to its own condition of life. Thus, I have found 

 lately that a Millepora coral exists extensively on the extreme South of 

 New Zealand. This is the only species known to me outside the tropics. 

 If the species were found fossil, we should certainly say that it gave 

 evidence in favour of a warm climate. Cumulative evidence from the 

 whole forms of life are the only safe grounds on which climatical con- 

 clusions can be formed. 



EXPLANATION OF PLATES. 

 Plate I. 



Fig. 1. Deltocyathus Aiding ensis, a. coral, b. calice, both much 

 enlarged. 



Fig. 2. Cyathosmilia laticostata, a. coral, b. calice, much enlarged, c. 

 section slightly enlarged to show the double septa. 



Fig. 3. Conosmilia contorta, nat. size. 



Fig. 4. Amphihelia striata, nat. size. 



Fig. 5. Bistylia adherens, a. coral, b. calice, both enlarged. 



Fig. 6. Cladocora contortilis, nat. size. 



Plate II. 



Fig. 1. Trochocyathus heterocostatus, a. coral, b., end view of calice 

 showing primary costae ; both much enlarged. 



Fig. 2. Amphihelia ziczac, a. branch, b., another partly ground 

 down to show secondary layer of dermic tissue. 



Fig. 3. Cyathosmilia tenuicostata, a. coral, b. section. 



Fig. 4. Deltocyathus alatus, a. calice, b. coral. 



Fig. 5. Deltocyathus Tateanus, a. calice, b. base, both much 

 enlarged. 



