184 THE VOYAGE OF H.M.S. CHALLENGER. 
sinuous in their course in the upper part of the calicle. Their edges are very finely 
denticulate, some of them are very thick; they are prolonged to the very tips of the 
branching processes, where they have short septa of inferior order intercalated between 
them (fig. 2b); they lap round over the margins of the processes a short distance so as to 
notch them (fig. 2c). There is no trace in either of the two specimens obtained of any 
development of additional individuals, and of a compound corallum. 
Extreme height of two specimens, 25 mm. and 22 mm. respectively. Extreme 
breadths, 25 mm. and 20 mm. 
Locality unknown. The specimens were received from Captain J. F. L. P. Macleat, 
R.N., Commander of the Challenger. 
Astrea, Milne-Edwards and Haime. 
Astrea abyssorum, un. sp. (Pl. X. figs. 4, 4a). 
The corallum is white, and forms smal] elevated masses composed of from about fifteen 
to twenty-five calicles. The budding takes place at the point of union of several calicles. 
The calicles are subpolygonal, with irregularly prominent margins, the surface of the 
corallum being thus very uneven. The fossee are deep, widely open, and conical. The 
septa are deeply dentate near the columella, and become gradually less so towards the 
margins of the calicles. The quaternary septa are fused to the tertiaries at a short 
distance above the columella. The septa are stout, and thickly beset with granules. 
The columella is‘composed of numerous papillee which occupy a wide area. 
Height of the largest specimen, 24 mm. Average diameter of the calicles, 6 mm. 
Diameter of the largest calicle, 9 mm. 
Station 190, Arafura Sea. 49 fathoms. 
Station 192, off the Ki Islands. 129 fathoms. 
Cladocora, Milne-Edwards and Haime. 
Cladocora arbuscula, Milne-Edwards and Haime. 
Simon’s Bay, Cape of Good Hope. 10 to 20 fathoms. A single specimen. 
Station 33, off Bermuda. 435 fathoms. A dead fragment of the same, possibly not 
living at that depth. 
Cladocora debilis, Milne-Edwards and Haime. 
A single specimen, fresh, and evidently recently living, is included amongst the 
products of a dredging off the mouth of the Rio de la Plata in 600 fathoms. The 
specimen has abundance of a corallinaceous sea-weed .attached to it, and I feel uncertain 
