116 PT7BLIN UNIVERSITY 



Another form to which I would next direct attention is one in which 

 I find a single, but important, difficulty, in referring to the genus Sphoc- 

 rozosma, and it is the following : — I cannot find either one or two " glan- 

 dular processes" between the joints of the filament, the presence of which 

 is one of the characters of the genus Spha>rozosma (Corda). The filament, 

 which is very minute, is, however, plane and fragile ; while the joints, 

 which are about as broad as long, are constricted by a sharp, not deep 

 notch at each side between the projecting lateral inflations at the base 

 of the segments, giving a pinnatifid appearance to the margin of the 

 filament, which thus possesses all the characteristics of Sphserozosma, 

 save the one above noticed. Surrounding this form I do not think 

 there exists a gelatinous sheath ; but I am not able to affirm this at all 

 confidently. The ends of the segments are straight and abruptly trun- 

 cate, each in close apposition to the truncate end of the neighbour- 

 ing joint, without the apparent intervention of any "glandular pro- 

 cesses" (Fig. 7).* This form is very minute, and is very fragile; hence 

 seldom found having more than fifteen or twenty joints in the filament, 

 generally less ; often one single cell only is met with. The endochrome is 

 light-green, and possesses a single "vesicle" (or corpuscle) at the centre 

 of each segment. Its minute size, the absence of the conspicuous central 

 solitary "gland," its truncate and square-angled (not rounded) ends, 

 and the lateral pouting projections of each joint at the base of the seg- 

 ments, readily distinguish this form from Sphcerozosma vertebratum. It 

 differs from Spharozosma excavatum, which it more nearly approaches 

 in size, by its square ends and lateral protuberant inflations, with a sharp 

 notch at the constriction at each side, and in being wider at the basal infla- 

 tion of the segments than at the ends, not, as in Sphcerozosma excavatum, 

 with rounded ends wider there than at the centre, and having a deep 

 wide sinus at both sides of the joint. I may add that, so far as my 

 humble experience goes, the "junction- glands" of Sph&rozosma exca- 



• I would here remark that Spheerozosma pulchrum (Bailey), an American species, 

 is described and figured (Ralfs' " Br. Des.," Appendix, p. 209, Plate XXXV., Fig. 2, 

 a and b) as having straight junction-margins, connected by short bands, without any men- 

 tion of " glandular processes." In the drawing the joints are represented in both figures 

 as even without septa between them, giving the idea of a continuous compressed tube, 

 with lateral inflations, but which in this respect is surely erroneous; but which, if drawn, 

 would give a junction-margin somewhat like that described above. 



