CHARACTERISTIC DEEP-SEA TYPES. — HYDROCORALLINJE. 139 
(Fig. 444.) It has also been found by the “ Porcupine ” expedi- 
tion at from 500 to 600 fathoms, in the cold area to the north- 
ward of the British Islands. 
Fig. 444. — Pliobothrus symmetrieus. 4. (Pourtales.) 
The other family of the group added to the West Indian 
fauna by deep-sea dredgings is that of the Stylasterid® ; in 
some of the genera the simple circular digestive opening is 
drawn out into elongate chambers, while in some genera a 
Fig. 445. $. Fig. 445 a. 1. 
Cryptohelia Peircei. (Pourtalés. ) 
tongue-like process or a lid covers in part or wholly this 
opening. Such an expansion of one edge of the calycle to 
form a lip (Fig. 445), folded over the opening, we find in 
Cryptohelia Peircei. (Fig. 445 a.) 
Among the most beautiful and delicate of the milleporian 
corals found on rocky bottom is Stylaster filogranus (Fig. 
