724 



ORDER PERITRICHA. 



zooid attached to the lorica through the medium of a short, transversely 

 annulate, elastic pedicle, which in the extended state nearly equals the 

 body of the animalcule in height ; peristome-border very prominent and 

 massive, exserted but a short distance beyond the margin of the lorica. 

 Height of lorica 1-400". 

 Hab. — Salt water. 



The non-conformance of this type with the CotJiurnia pupa of Eichwald, as 

 tentatively suggested by Cohn in his description of this elegant type,* has necessi- 

 tated the substitution of the new title, associated with his own name, that is here 

 proposed. That it is perfectly distinct from the last-named species is at once 

 demonstrated on reference to the original figures and description of that form in 

 Eichwald's ' Infusorienkunde Russlands,' reproduced at PI. XL. Fig. 23. In the 

 present species the grooves or annulations are confined entirely to the posterior 

 portion of the lorica, which as a whole presents an elongate subcylindrical contour. 

 In Eichwald's C. pupa, on the other hand, the general contour is almost evenly 

 ovate, three prominent transverse annulations being distributed at equal distances 

 throughout its length. The lorica of the present species, as described by its dis- 

 coverer, is remarkable for its brilliant coloration, the margins, as in certain Crypto- 

 monads, reflecting a brilliant scarlet hue, while a paler roseate tint suftuses the 

 intervening area. 



Cothumia pupa, Eichw. Pl. XL. Fig. 23. 



Lorica symmetrically ovate, widest centrally, tapering evenly towards 

 each extremity, about twice as long as broad, sometimes slightly constricted 

 beneath the terminal aperture ; surface ornamented with three raised trans- 

 verse annuli, one encircling the centre of the lorica, the two others at equal 

 distances between the centre annulus and the anterior and posterior 

 extremities ; colour brown ; pedicle short, about one-fourth the length of 

 the lorica. Dimensions unrecorded. Hab. — Fresh water. 



Cothumia gracilis, S. K. Pl. XL. Fig. 12. 



Lorica attenuate, curved, three and a half times as long as broad, widest 

 and rounded posteriorly, gradually tapering towards the narrow and curved 

 anterior region, the anterior aperture minute, truncate, and not everted ; 

 pedicle short, thick, and transversely rugose ; animalcule, when contracted, 

 ovate, with a nipple-like anterior projection. Length of lorica 1-250". 



Hab. — Salt water, on minute Crustacea. 



The author obtained a single example only of this species, in February 1878, at St. 

 Heliers, Jersey, attached to a thoracic appendage of the crustacean Ncbalia bipes, 

 having there associated with it as messmates Spirochona Nebalii, previously described, 

 and the singular Trematode Saccobdella Ncbalice of Professor C. J. Van Beneden. 

 The exceedingly attenuate and graceful contour of the lorica of this species readily 

 distinguishes it from all previously recorded types, its curvature, however, to some 

 extent, approximating it to the CotJiuniia ciirva of F. Stein. The animalcule wvas 

 not observed in its expanded state, the crustacean to which it was attached having 

 unfortunately been immersed in a preservative fluid prior to its discovery. 



* ' Zeitschrift fiir Wissenschaftliche Zoologie,' Bd. xvi., 1866. 



