720 ORDER PERITRICHA. 



Cothurnia imberbis, Ehr. PL. XL. FIGS. 9 AND 10. 



Lorica ovate, about twice as long as broad, narrowest anteriorly, its 

 margin not everted, transparent when young, assuming a yellow tinge when 

 old ; pedicle shorter than the lorica, sometimes curved ; body of extended 

 animalcule projecting but little beyond the margin of the lorica ; endoplast 

 linear, slightly curved. Length of lorica 1-288" to 1-240". 



HAB. Fresh water, on Entomostraca and aquatic plants. 



This, the most familiar representative species of the genus Cothurnia^ is frequently 

 found in great abundance on the Entomostracon Cyclops quadricornis. It is not, 

 however, confined to an animal host, being as often met with upon the thread-like 

 filaments of various species of Conferva. The pedicle is occasionally so short as to 

 present a mere button-like aspect. Sometimes it is continued through the wall of 

 the lorica, thus imparting to the animalcule a doubly pedicellate character. 



Cothurnia maritima, Ehr. 



Lorica ovate, transparent, one and a half times as long as broad, slightly 

 inflated posteriorly ; pedicle much shorter than the lorica ; parenchyma 

 hyaline, whitish. Length of sheath 1-570" to 1-350". 



HAB. Salt water, on algae, &c. 



Excepting for its smaller size, this species closely resembles C. imberbis. It was 

 observed by the author of specimens developed in great abundance in a jar contain- 

 ing decomposing algae, at St. Heliers, Jersey, that the cuticular surface as viewed 

 with a j-inch objective was distinctly striate in a transverse direction. 



Cothurnia havniensis, Ehr. PL. XL. FIG. 19. 



Lorica wineglass-shaped, transparent, truncate and widest anteriorly, 

 scarcely one and a half times as long as broad ; pedicle slender, three or 

 four times the length of the hyaline sheath ; body whitish. Length of 

 sheath, without stalk, 1-280". HAB. Salt water. 



This species was obtained by Ehrenberg in company with Acineta Lyngbyei on 

 Ceramium and Sertularian zoophytes at Copenhagen. According to his figures 

 given, here reproduced, the animalcule presents a much more broadly ovate form than 

 obtains among all ordinary Cotkurnice, and occupies only the distal portion of the 

 lorica. Excepting for the presence of the anterior fringe of cilia, the general contour 

 of both the lorica and contained zooid corresponds with that of a long-stalked 

 Acineta, and as an imperfectly observed representative of which genus the author 

 is much inclined to regard it. 



Cothurnia Sieboldii, Stein. PL. XL. FIGS. 24 AND 25. 



Lorica gibbously urceolate, strongly compressed in front, dilated pos- 

 teriorly, more especially on the dorsal aspect ; the two frontal angles 

 extended upwards and outwards, and again curving inwards at their 

 extremities, so as to resemble two horns ; walls of the sheath hyaline when 

 young, turning from yellow to deep rusty brown with age ; pedicle colour- 

 less, short, thick, curved, and transversely wrinkled, much thickened at its 

 point of juncture with the sheath ; body of animalcule small in comparison 



