1gt0o. | 
N. ANNANDALE: Phylactolematous Polyzoa. 47 
the cold weather, beginning to flourish in November and dying 
down again about March. I have not seen resting statoblasts. 
in this species. 
Plumatella emarginata, Allman. 
Plumatella emarginata, 4i/man, op. cit., p. 104, pl. vii, figs. 5—10. 
Alcyonella benedeni, zd., ibid., p. 89, figs. 5—II. 
Plumatella princeps var. emarginata (partim), Kraepelin, op. cit., 
p.- 
120, pl. iv, fig. 108. p!. v, fig. 123. 
Plumatella emarginata, Braem, op. cit., p. 9, pl. i, figs. 12, 14. 
Plumatella emarginata (partim), Annandale, op. cit., p. 89. 
The main characters of this species, which is remarkably con- 
stant, 
are the following :—- 
(1) The zocecia are slender and nearly cylindrical, often 
quite straight, never dilated at the tip, often (in young 
or poorly developed colonies) adherent to the support 
of the zoarium by their whole length. The distal 
part of each zocecium is never strongly bent upwards 
when the base is recumbent. 
(2) The aperture is frequently situated on the dorsal surface 
of the zocecium rather than at the tip. 
(3) The ectocyst is stiff. It is deeply pigmented at the base 
of each zocecium but colourless at the tip. 
(4) The ectocyst is defected on a triangular area situated at 
the tip of each zocecium on its dorsal surface,! the 
apex of the triangle, which points away from the 
aperture, being frequently produced as a furrow 
running along the middorsal line of the zocecium. 
The defective area is hyaline, but the furrow is 
never very deep. 
(5) The statoblast is invariably elongate (not less than 14 
times as long as broad), and (the capsule being small 
and relatively short) the swim-ring is usually much 
narrower at the sides than at the extremities. 
(6) In well-developed zoaria part of each zoarium is usually 
flat and recumbent and part upright, the upright part 
consisting of branches ramifying in one plane. 
(7) The main axis of the branches forms an angle less than a 
right angle with that of the zoarium, and is approxi- 
mately straight. 
In this species the distinction between the dorsal and the ventral 
surface of the zocecium is often retained, even in the case of entirely 
free zocecia, more clearly than it is in allied forms, the ventral surface 
keeping its flattened appearance. ‘The coloration is characteristic. 
The basal part of the zocecium varies from a fairly pale brown to 
nearly 
black in tint, but is always opaque and contrasts with the 
white tip, which is by no means coterminous with the emargination. 
1 This is what is meant by calling the zocecium emarginate. 
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