MARINE PROTOZOA FROM WOODS HOLE. 
449 
Condylostoma patens Muller. (Fig. 45.) 
The body is elongate, somewhat sac-like, five or six times as long as broad, plastic, and frequently 
contains brightly colored food granules. The triangular peristome takes up the greater part of the 
anterior end, and the mouth is situated at the sharper angle of the triangle, about one-fourth of the 
total length from the anterior end. The cuticle is longitudinally striated, the lines having a slightly 
spiral course. They are not closely set, and fine cilia are thickly inserted along their edges. The 
endoplasm is granular and viscous. The motile organs consist of an adoral zone of membranelles, 
Which stretch along the left edge of the peristome and the front edge of the body. The right edge of 
the peristome supports an undulating membrane. The nucleus is moniliform and extends the full 
length of the leftside; a number of micronuclei are distributed along its course (Maupas). 
Length 400/;; diameter at widest part 105/;. Maupas gives the length from .305/; to 495/;; and 
Stein 376/; to 564/;. Very common. 
For a more extended account of the structures, see the excellent description by Maupas ’83. 
Key to the marine genera of Stentoridx. 
Diagnostic characters: The peristome is relatively short and limited to the front end of the animal, so that its plane is 
nearly at right angles to that of the longitudinal axis of the body. The adoral zone of cilia either passes entirely around 
the peristome edge or ends at the right-hand edge. The surface of the peristome is spirally striated and provided with 
cilia. Undulating membranes are absent. 
1. Peristome circular in outline; limited to the anterior end -. Genus Stentor 
2. The peristome is drawn out into two wing-like processes; tube-dwelling Genus Folticulina 
Genus STROMBIDIUM Cl. & Lach. ’58. 
(Stein ’67; Biitschli ’73; Fromentel ’74; Kent ’81; Gruber ’84; Entz ’84; Maupas ’83, Biitschli '88. ) 
Small, colorless (except for ingested food) animals with characteristic springing movements. The 
form is usually constant, but in some cases may be plastic like Astasia; it is usually globular or conical, 
the posterior end being more or less pointed, the anterior end broadest. The latter is surrounded by a 
complete circle of the adoral zone, the oral end of which passes into a peristomial depression which 
extends deep into the middle of the body. The mouth, with a very small oesophagus, lies at the bottom 
of the inturned peristome. The region surrounded by the adoral zone is frequently drawn out into an 
anterior process, occasionally bearing a pigment mass. The ventral surface in some cases bears cilia, 
which may be distributed or restricted to a row of large cilia. Trichocysts are usually present and 
F. C. B. 1901—29 
