352 ORDER CHOANO-FLAGELLATA. 



length of the lorica; contractile vesicles two in number, posteriorly 

 situated. Length of lorica 1-800" to 1-500", of body of contained 

 animalcule 1-2000" to i-iooo", 



Hab. — Fresh water, occurring singly or in small groups of three or four 

 individuals. 



The figures illustrating this species, contributed by Prof. H. James-Clark to the 

 Memoirs of the Boston Society of Natural History for the year 1868, convey but an 

 inadequate idea of the very considerable variation in contour that may be assumed by 

 the protective lorica, he in all instances delineating and describing that form in which 

 the posterior extremity is so attenuate as to constitute a veritable pedicle, as shown 

 at PI. VI. Figs. 26 and 27. Although frequently met with in the condition that 

 has been alone encountered by the American authority, the examination of many 

 hundred examples by the present author has elicited the fact that in at least British 

 waters this very attenuated form is more exceptional, the majority tapering but 

 moderately as in the example represented at Fig. 28 of PI. VI. or being evenly 

 rounded in this region as at Fig. 32. This species, in common with S. amphoridium, 

 appears to be almost universally distributed, examples having been found attached 

 mostly to confervoid algre, obtained from numerous widely separated stations, some- 

 times occurring as solitary samples, and in other instances in little closely approxi- 

 mated clusters of three or four individuals, as in the figure last referred to. These 

 social groups are the product by repeated transverse fission or gemmation of 

 a single primary zooid in the manner indicated in Figs. 28 and 29, and as more 

 fully described in connection with the marine type Salpingoeca inqiiillata. The 

 motile zooid or germ derived from this fissive process presents, in the first instance, 

 a simple monadiform aspect, as shown at Fig. 30, and fastening itself close to the 

 base of the parent lorica, speedily acquires all the essential characters of the adult 

 organism. Encysted examples exhibiting a more or less advanced stage of segmen- 

 tation, as shown at Fig. 31, are of frequent occurrence. Stein, in his recently 

 published volume, connects with the present title examples only having a distinct 

 peduncular posterior prolongation ; the intermediate variety, as reproduced from his 

 work at Fig. 24, being distinguished by the title of Salpingoeca vaglnicgla. 



B.— Pedicle persistent, conspicuously developed. 

 Salpingoeca marina, J.-Clk. Pl. III. Figs. 13-15, and Pl. V. Fig. 34. 



Lorica ovate, inflated and widest posteriorly, tapering evenly towards 

 the aperture at the opposite or anterior extremity, mounted on a straight 

 or irregularly curved pedicle, which equals or slightly exceeds the lorica in 

 height ; animalcule adapting itself to the shape of the lorica, and almost 

 filling it. Length of lorica 1-4000" to 1-3250". 



Hab. — Salt water, attached to the hydrothecae of Sertularian zoophytes, 

 solitary. 



In Salpingoeca amphoridium and S. gracilis the occasional or more abnormal 

 occurrence of a very short or more or less conspicuously developed pedicle, has 

 been already alluded to ; with S. marina, however, we arrive at a group of forms 

 in which a pedicle is constantly present, and usually of considerable length. But 

 for this feature being inconstant in the two above-named species, it might have 

 been desirable to create a new generic title, for either the pedicellate or non- 

 pedicellate series, equivalent in value to Cothurnia and Vaginicola among the 

 higher Ciliate types. These exceptional instances, however, serve well to illustrate 

 the unreliability of such characters for the purposes of classification. The specimens 

 of Salpingoeca marina as first described and figured by Prof H. James-Clark, agree 

 in all respects with those obtained by the author in British waters, with the 



