REPORT ON THE POLYZOA. 
57 
and apparently alive in Canada balsam, having previously stained the tissues with 
carmine. All the details of its anatomy, consequently, are beautifully displayed. The 
polypide has about twenty-four tentacles, a rather wide oesophagus, and a simple saccular 
stomach, without any diverticulum, and the rectum opens very low down into the 
tentacular sheath. The retractor muscles consist of long, slender, non-striated fibres 
each of which presents a single nucleus at some part of its length (fig. Ad). Besides the 
muscular fibres, there is no appearance of a so-called funiculus. 
The peculiar horse-shoe-shaped mark visible in a few of the zocecia appears to 
represent a flattened cavity on the inner face of the anterior wall, and probably lying 
between the ectocyst and endocyst, if the calcareous wall be taken to represent the former. 
In the older zocecia this cavity is quite empty and clear, but in one or two of the marginal, 
immature zocecia, in which the polypide is still represented merely by an elongated 
mass of granular matter (fig. Ah), the faintly seen but distinct horse-shoe-shaped organ 
appears to contain a collection of extremely minute granules. There is no direct indication 
whatever that these organs are of an ovarian or testicular character, and in the whole zoarium 
I have been able to perceive their existence in not more than about six or seven cells. 
The lateral and central apparent puncta in the anterior wall have all the characters of 
the ordinary form of interzooecial pores or discs (“ Rosettenplatten ”), and like those struc- 
tures may be described as perforations in the calcified wall or ectocyst, filled in, however, by 
a delicate membrane, or rather double membrane, between whose layers are lodged eight to 
ten minute spherical granules, deeply coloured with the carmine (fig. 4c). The outer layer 
is in this case formed apparently by a very delicate epitheca, and the inner by the equally 
delicate endocyst. 
In several of the zocecia the polypides appear to have been killed so suddenly that 
they have not had time to retract themselves wholly into the cell, so that the extremities 
of the tentacles have been caught by the sudden closure of the operculum. 
(6) Carbasea pisciformis, Busk. 
Carbasea pisciformis, Bk., Brit. Mus. Cat., vol. i. p. 50, pi. Iv. figs. 1, 2 ; pi. lvi. fig. 6; Macgilliv., 
Nat. Hist. Viet., Dec. v. p. 30, pi. xlv. fig. 6. 
Character. — Zoarium broadly lobate, lobes rounded, entire at the margin. Zooecia 
elongated, pyriform, truncated at both ends, and much contracted near the bottom, 
which is again slightly expanded. Ooecia immersed, marked with radiating lines. 
Habitat. — Station 162, off EastMoncceur Island, Bass Strait, 38 fathoms, sand, shells. 
[Tasmania, Brit. Mus. Collect. ; Queenscliff, Portland, Victoria, Maplestone.] 
The polypide has about twenty-four tentacles, and the stomach a long diverticulum. 
The retractor muscular fibres are very numerous and slender, and neither nucleated nor 
(ZOOL. CHALL, EXP. — PART XXX. 1884.) Gg 8 
