REPORT ON CORALS—EXPLANATION OF PLATES. 243 
9. A very slender young specimen. 
10. One of the calicles of the same. 
11. Enlarged view of part of the surface of the same to show the striations. 
12. An old and very massive specimen, much thickened by growth of ccenenchym. 
13. Mouth of one of the calicles of the same. 
PLATE X. 
Fig. 1. Sphenophyllia flabellum. a Under surface of the same. 06 Mouth of the calicle. 
Locality unknown. 
Figs. 2, 3. Tridacophyllia cervicornis. Locality unknown. 
2. a The same, enlarged view into the mouth of the calicle. 6 Tip of one of 
the processes of the margin of the ealicle, viewed from the inner surface to 
show the septa. c¢ Back of the same process. 
3. A smaller specimen of the same coral. a View into the mouth of its calicle. 
Fig. 4. Astrea abyssorum. «a Enlarged view of a calicle of the same. Arafura Sea. 
49 fathoms. At the foot of the plate the older term of MM. Milne-Edwards 
and Haime, Siderastrea, is printed by inadvertence. 
Fig. 5. Cladocora conferta. a Enlarged view of a calicle of the same. Off Samboangan, 
Mindanao, Philippines. 30 fathoms. 
6. Cycloseris tenuis. a Under surface of the same. Off Tongatabu, Friendly 
Islands. 18 fathoms. 
Fig. 7. Neohelia porcellana. a Enlarged view of a calicle of the same. Off Api 
Island, New Hebrides. 63 fathoms. 
PLATE XI. 
Fies. 1-13. Bathyactis symmetrica. A series from various localities to show the 
_variations in size and form. 
1. A large specimen, upper surface twice the natural size. a@ Under surface of 
the same. Lat. 46° 16’ S., long. 48° 27’ E. 1600 fathoms. 80 miles west 
of Hog Island, Crozet Islands. 
2. One of the largest specimens dredged. Lat. 36° 44’ S., long. 46° 16’ W. 
2650 fathoms. South Atlantic Ocean, east of the Rio de la Plata. 
3. Specimen showing a regular and symmetrical fusion of the upper margins of 
the inner parts of the septa as in Deltocyathus. Lat. 33° 31’ S., long. 74° 
43’ W. 2160 fathoms. Between Juan Fernandez Island and Valparaiso. 
4, Deformed specimen, which has been fractured and was reunited. — Lat. 
