COLUEIDiE. 47 



dered uneven by fine depressions ; and tlie posterior end of the crest projects somewhat 

 beyond the base of the foot. 



Length (of lorica), jj^ inch. Habitat. Berlin (Ehr.). 



Metopidia coenuta, Schmarda (PI. XXXIV. fig. 3). 

 Lepadella cornuta Schmarda (135). 



RP. CH. Lorica oval ; its anterior margin with two great spines. 



Body yellowish grey. A deep gap separates the two curved frontal horns. The 

 unci are one-toothed. Schmarda says that there are two contractile vesicles at the 

 foot ; and he draws two small vesicles in that position. Unfortunately he does not say 

 ■whether he has seen them contract or not ; nor whether they did so independently of 

 each other. The only similar case of such a construction, that I am acquainted with, 

 is that of Conochilus volvox (according to Cohn, vol. i. p. 90, foot note). 



Length (total), yuo inch. Habitat. Brackish water. New Orleans (Schm.). 



Metopidia oblonga, Ehrenberg (PI. XXXIV. 5). 

 Squamclla oblonga Ehrenberg (42). 



SP. CH. Lorica elliptical, or ovatcly oblong, hyaline; toes long, slender; eyes 

 foiir. 



There are two or three teeth in each uncus ; the gastric glands are pear-shaped ; 

 and there are four frontal eyes arranged in the angles of a parallelogram. Ehrenberg 

 has seen a contractile vesicle, and lateral canals. 



Length (total), ^f^, inch. Habitat. Berlin (Ehr.). 



Hexastemma melanoglena, Lepadella mucronata, L. setifeba, Squamella 

 quadeidbntata, Schmarda (135). These possibly may be MetopidicB, but see note 1, 

 Supt, p. 8. 



MoNURA DULCis, Ehrenberg (42), (PI. XXXIV. fig. 9). 



SP. CH. Lorica ovate, obliquely truncate behind, acute ; eyes distant. 



The dorsal outhne (a long narrow oval, truncate at both ends), the pointed termina- 

 tion of the lorica (seen at the side view), and the wide separation of the eyes, sufficiently 

 distinguish this species ; which, Ehrenberg thought, might be marine as well as lacus- 

 trme. 



Length, ^1^ inch. Habitat. Near Berlin ; possibly Cattaro (Ehr.). 



Genus DISPINTHERA, Gosse (171). 



GEN. CH. Body sub-cylindric, inclosed, in part, within a lorica open in front and 

 in rear, apparently cleft down the venter ; head and foot habitually protruded ; head 

 distinct, protected by horny plates, but without a frontal hook; tivo cervical eyes. 



Dispintheea capsa, Gosse (171), (PL XXXI. fig. 48). 



[SP. CH. Lorica in most parts soft and flexible ; foot sto2it ; toes tivo, furcate, 

 thick, straight, tapering, acute. 



This apparently new form I found in the sediment of water dipped by Mr. Bolton 

 from " ditch No. 2," in Sutton Park, Birmingham, crowded with fine Desmidieae. The 

 facies strikes one as very peculiar, and difficult to explain. The front is capable of 

 much protrusion, in a conical form, where a globose tiibercle is visible, but only occa- 

 sionally, and a similar one, but more constant, on the occiput (or rather crown of the 

 head), just below the point of the occipital sheath. The lorica is discernible chiefly 

 about the head ; it tliere projects into several points, which seem very flexible, but 

 constant. When the head is far retracted (which is seldom), an array of spears is left 

 bristling up. Now and then, at the pectus, the integument is seen to fall into a flap, or 



