GENUS FOLLICULINA. 599 



twice as long as broad, their extremities broadly rounded ; endoplast 

 spheroidal, subcentral. Length of entire lorica 1-192" to 1-120". 

 HAB. Salt water. 



The favourite haunt of this species is, according to Stein, among the angles 

 formed by the finer divisions of the fronds of Ceramium, Polysiphonia, and other 

 filamentous seaweeds. It frequently happens, as shown at PI. XXIX. Fig. 35, that 

 the attached basal portion of the lorica is supplemented anteriorly by a small keel- 

 like lamina of similar consistence, and presenting in profile the aspect of a 

 triangular, wedge-shaped fulcrum, while in the rear the lorica is made fast to the 

 object of support by a backward directed lamina of similar shape and character. 

 The examples of this species, as met with by Stein, and Claparede and Lachmann, 

 by the former in the Baltic, and by the latter authorities in the North Sea, present 

 some slight differences in both the character of the lorica and contained animalcule. 

 In the original form of Freia (Folliculina} elegans, as described by the Swiss autho- 

 rities, a conspicuous lunate excision was always observed on the left-hand side of 

 the aperture of the lorica, two or more triangular valve-like laminae projected 

 forwards from within the interior of the short tubular neck, while the contractile 

 vesicle was simply spherical and situated on the median line a little behind the 

 endoplast. In the examples referred to this type by Stein, on the other hand, 

 the oral aperture of the lorica is even and entire, a single sickle-shaped valvular 

 lamina projects backwards from the upper wall of the interior of the neck, 

 while the contractile vesicle is stationed on the ventral side of, and slightly 

 in advance of, the central endoplast, and, in place of being simply spheroidal, 

 exhibits at diastole supplementary lateral extensions. If not entitled to the rank 

 of an independent species, Stein's type would appear to represent at the least a 

 well-marked local variety. 



Folliculina producta, Str. Wright sp. PL. XXIX. FIGS. 29-32. 



Lorica pale yellow-brown, inflated at its base, produced anteriorly into 

 a neck-like extension, often equal to five or six times the length of this 

 body portion ; the neck regularly and transversely annulate throughout its 

 extent ; animalcule deep blackish-green, exceedingly attenuate, projecting 

 to a considerable distance beyond the aperture of the lorica ; peristomal 

 lobes much prolonged, of equal size, ligulate or ribbon-like, curved at 

 their extremities. Length of fully developed lorica i-ioo". 



HAB. Salt water : Queensferry, Ireland (Strethill Wright). 



While the transversely annulate neck-like prolongation of the lorica of this 

 species approximates it somewhat to one variety of Folliculina ampulla, it may be 

 readily distinguished from that type by the extraordinary development of this 

 region, which often contains as many as twenty-seven transverse annulations. The 

 lobes of the peristome are also, in comparison with that form, much more 

 lengthened and attenuate. Several phases of the free-swimming larval condition of 

 Folliculina producta have been observed and figured by its discoverer, Dr. Strethill 

 Wright, and will be found reproduced at PI. XXIX. Figs. 30-32. At these early 

 periods of its existence there was no trace of a sheath or of the ear-like peristomal 

 lobes; the animalcule being either ovate or of cylindrical form, pointed at the 

 posterior extremity, and abruptly truncate at the anterior one, which bore rather 

 larger cilia than those of the general surface of the body. One of these larvae was 

 observed to attach itself and complete the construction of its lorica, including the 

 prolonged annulated neck, within the course of a single night. Whether the free- 

 swimming peristomeless larvae are produced by fission or through internal gemmation 

 from the parent form remains to be discovered. 



