462 
BULLETIN OE THE UNITED STATES FISH COMMISSION. 
brownish lorica of quite variable form but always attached. These houses may be finger-formed, with 
widened center, or widened mouth, or constricted mouth, and the like. Ring-formed swellings are 
frequently developed. Sometimes the mouth becomes twisted and the lorica is therefore bilateral. 
The houses are attached either directly to some foreign object or by means of a short stalk. The 
animals are similarly fastened to the lorica, sometimes directly, sometimes by means of a short stalk. 
When they contract they draw back to the bottom of the lorica; when expanded they usually stretch 
out of the mouth opening. In some forms there is an operculum, by means of which the opening of 
the shell can be closed when the animal is retracted. Fresh and salt water. 
The number of species of Cothurnia has become so great that the difficulty in placing forms is 
almost sufficient to discourage the systematist; as Biitschli well remarks, the variations in the theca 
have been made the basis of new species so many times that the genus is almost as confused as Difflugia 
among the rhizopods or Campanularia among the hydroids. The length of cup, of stalk, the presence 
of annulations on stalk or cup, etc., have given rise to many specific names, the majority of which I 
believe can be discarded. According to such differentials the same branch of an alga holding a 
hundred specimens of Cothurnia crystallina yield 10 or 12 species, whereas they are merely growth stages 
of one and the same form. 
Cothurnia crystallina Ehr. Fig. 62. 
Synonyms: Vaginicolla crystallina Ehr., Perty, Eichwald; V. grandis Perty; V. pedunculata Eichwald; Cothurnia 
crystallina Clapar&de & Lachmann, D’Udek.; C. gigantea D’Udek; C. maritima, C. crystallina Cohn; C. grandis Meresch. 
The form of the cup shows the greatest differences; sometimes it is cylindrical, sometimes elongate 
thimble-shape, sometimes pouch-shape, corrugated or smooth on the sides, and wavy or smooth on 
border. F requentl v the basal part be- 
comes stalk-like, but this is very' short. 
When present, the stalk may or may 
not have a knob-like swelling. The 
animal within the cup may or may not 
be borne on a stalk, and this stalk may 
or may not be knobbed. The cups are 
colorless or brown. The animal is very 
contractile and may stretch half its 
length out of the cup or retract well 
into it. There is no operculum. The 
length of the cup varies from 70/4 to 
200/4 (C. gigantea; Vag. grandis, etc.). 
From Entz. 
There is nothing to add to Entz’ s 
characterization of this species, which 
is found both in fresh and salt water. 
The variability of the cup and stalk is 
quite noticeable in the Woods Hole 
forms. 
Cothurnia imberbis Ehrenberg, var. 
curvula Entz. Fig. 63. , 
Synonyms: C. imberbis Kent et al.; C. 
curvula Entz; C. socialis Gruber? 
The lorica is swollen posteriorly, 
narrowest at the oral margin, bent on 
its axis and is supported ou a short 
stalk. It is perfectly smooth and with- 
out annulations. The animal itself has no definite stalk. When fully expanded the animal emerges' 
but slightly from the margin of the cup. Fresh and salt water. On red algae. Dimensions of Woods 
Hole form: Cup 50 to 55/4 long; greatest diameter 22/4; length of stalk 4 to 5/4. 
