79 
Plumatella auricomis, Annandale. 
1913. Annandale, Journ. As. Soc. Bengal (n. s.) VIII, p. 227, pl. vii, 
fig. 2. 
The material from which this species was recently descrihed was 
somewhat imperfect, but the Volga collection, in which it is represented 
by а well-preserved colony, enabl.es me to give further details. 
The colony forms а small adherent growth of somewhat open den- 
dritic outline, the branches and twigs being distinctly separate from one 
another. The individual zooecia are neither markedly elbowed nor elongate; 
they are almost circular in vertical section, but а little flattened below; 
there is no trace of either keel or furrow on the upper surface. The ecto- 
cyst is hyaline and almost colourless, but in the older parts of the colo¬ 
ny it has on the proximal part of zooecia а slight brownish tinge. It is 
distinctly separated into two layers, an inner hornyone about 0.20 mm. 
thick and an outer gelatinous one about 0.28 mm. thick. The polypide 
preserves its characteristic yellowish colour to some extent even in for¬ 
malin. Tke free statoblasts are small and closely resemble those of P. 
diffusa, having the swim-ring distinctly wider at the ends than at the 
sides and being moderately elongate. The free surface of the capsule is 
minutely tuberculate. The average length is about 0.314 and the average 
breadth 0.17 mm.; the swim-ring is about 0.088 mm. wide at the sides 
and 0.06 mm. at the ends. 
P. auricomis was originally found on Shells of Unio terminalis, 
Brgt. in the Lake of Tiberias in Palestine. А colony from the Jeruslan 
river, taken with several colonies of P. casmiana on the leaf of а water- 
plant, affords the only other locality record as yet available. 
Considered as а whole, the collection of Polyzoa submitted to me is 
of considerable interest. All the species represented are, as might be ex- 
pected, true Palaearctic forms, and only one of them (Plumatella puncta¬ 
ta) has as yet been found within the limits of the Oriental Region. In 
that region the species of Plumatella that have elongate statoblasts pre- 
dominate over those in which these bodies are broad and have а swim- 
ring of uniform width. The only species (P. casmiana) in the Volga fauna, 
so far as it is yet known, with elongate statoblasts has the swim-ring 
much reduced and of uniform diameter; whereas in most of those in which 
the length greatly exceeds the breadth, the swim-ring is much wider at 
the ends than at the sides. (This is the case, for example, in P. fruticosa 
and P. emarginata, species that are common and widely distributed both 
in Europe an North America and also in India) P. casmiana in respect to 
its free statoblasts Stands alone, and it is remarkable that it should have 
