CHARACTERISTIC DEEP-SEA TYPES. — CRINOIDS. ar: 
of two characteristic species of these worms, strangely modified 
to adapt themselves to the peculiar conditions of their habitat. 
The organs of the body are arranged radially, and the mus- 
cular system so admirably adapted for attachment is wanting in 
Fig. 419. — Myzostoma filicauda. Fig. 420.— Myzostoma Agassizii, 
12, (Von Graff.) AP, (Von Graff.) 
the type which moves about freely on its host. In another 
group, a male and female inhabit a common cyst, caused by the 
presence of the parasite on the arm-joint or pinnule. Myzos- 
toma filicauda, the host of Antedon Hagenit, is one of the 
species with caudal append- 
ages (Fig. 419), while Myzos- 
toma Agassizil represents a 
type with long filiform cirri. 
(Fig. 420.) Another group 
forming no cyst has only short 
cirri. The cysts are sometimes 
sausage-shaped and situated on sh UTE — 4 
the dis ot the host, or, Dies Myzostoma eystieolum. $. (Von Graf.) 
the cyst formed by M. eystico- 
lum (Fies. 421, 421 a) on the arms of Actinometra meridio- 
. o 4 
nalis, they resemble plant galls. 
Parasite of Aetinometra meridionalis. 
