346 ORDER CHOANO-FLAGELLATA. 



Examples in which, as at PI. V. Fig. 3, the lorica is mounted on a very short or 

 rudimentary pedicle, are not unfrequently met with among the more ordinary sessile 

 specimens. 



Salpingoeca fusiformis, S. K. Pl. V. Figs. 27-31. 



Lorica sessile, subfusiform or vase-shaped, widest centrally, tapering 

 equally towards the two extremities, but expanding again anteriorly into a 

 somewhat prolonged and everted neck ; contained animalcule flask-shaped, 

 as in vS. ampJioridium, but of larger size. Length of lorica 1-1600". 



Hab. — Fresh water, solitary. 



The elegant vase-like contour of the lorica of this species readily distinguishes 

 it from the preceding form. Though tapering gradually to a slender point at the 

 posterior or proximal extremity, it has not yet been found in any instance to develop 

 a distinct pedicle, as not unfrequently occurs with Salpiugccca aniphoridiiwi. It is, 

 furthermore, much less plentiful than that species, and must be described as of 

 solitary rather than gregarious habits. The withdrawal of the flagellum and collar, 

 and the exudation of the sarcode, in a manner parallel to that already described of 

 S. ainphoridiiim, have been repeatedly observed. One of the more prominent 

 phases of these protean changes will be found illustrated by Fig. 28 of PI. V,, 

 in which instance the superabundant sarcode is exuding in the shape of an irregular 

 lobate process, while in Fig. 27, representing the same zooid as observed fifteen 

 minutes later, and in which the excurrent sarcode has broken away, the animalcule 

 has once more assumed its normal shape and condition, the body now filling little 

 more than half of the cavity of the lorica. Still more recently, April 1877, an 

 example of multiple fission or breaking up of the parent zooid into spore-like 

 bodies, preceded by retraction within its lorica and a process of encystment, has 

 been observed. Fig. 31 represents an interesting phase of this process, in which 

 the numerous monoflagellate zooids, the result of such a sporular mode of repro- 

 duction, are issuing from the aperture of the lorica. The pulsations of the contractile 

 vesicle in this species occur at longer intervals than in S. aniphoridiiun, a period of 

 from eighty to one hundred seconds being, as so far observed, the average time 

 occupied between the systole of each individual vesicle. 



O." Biitschli * has recently described an animalcule identical with the present 

 form under the name of Salpi}igoeca Clarki : the present title, bestowed upon it in the 

 author's communication to the Linnaean Society in June 1877, quoted also in the 

 'Annals of Natural History' for January 1878, necessarily, however, takes precedence 

 of this later one. 



Salpingoeca Steinii, S. K. Pl. V. Figs. 10-12. 



Lorica sessile, subfusiform or vase-shaped, about two and a half times 

 as long as broad, attenuate and pointed posteriorly, tapering towards the 

 anterior region, but expanding again and forming an everted neck ; 

 contained zooid flask-shaped, with an inflated basal and attenuate neck- 

 like portion occupying about one-half of the cavity of the lorica ; con- 

 tractile vesicles two or more in number, posteriorly located ; endoplast 

 spherical, subcentral. Length of lorica 1-600". 



Hab. — Fresh water, forming gregarious rosette-shaped clusters. 



This species, figured by Stein "j" as synonymous with the Salpingoeca ai72phondium 

 of H. James-Clark, is evidently a perfectly distinct type, whose more elongate lorica 



* ' Zeitschrift fiir Wissenschaftliche Zoologie,' Bd. xxx., 1S78. 

 t 'Infusionsthieie,' Abth. iii., 1878. 



