232 



the daughter-zooecium. This incompleteness most often means the absence of the 

 mandible and transverse bar in the aperture, and as a rule also a more or less 

 incomplete calcification of the wall separating the scapular from the infra-scapular 

 chamber. The infra-scapular and the pedal chambers, whose boundary ridges 

 towards the frontal surface of the zocecium give the latter a rhombic form, are 

 separated by a ridge running obliquely basally and proximally. These chambers 

 take up not only the lateral surfaces but also the greater part of the basal sur- 

 face, along the middle of which they are separated by a rather narrow longi- 

 tudinal belt (PI. XI, figs. 4 a, 4 b). The infra-scapular chamber communicates 

 with the zocecium by up to 10 rosette-plates and with the avicularium by only 

 1 — 2. The mother-zooecium is provided with a long, narrow, adzocecial, infra- 

 scapular chamber. 



The ooecium. The gonozooecium, which is considerably smaller than the 

 covering kenozocBcium, is situated sometimes on a mother-zooecium, sometimes 

 on an inserted single zocecium. The aperture has a very broad and deep sinus, 

 consisting of a wider outer part, which is bounded by two arch-shaped, in- 

 wardly converging margins, and of a narrower inner part, which has a small, 

 rounded process on either side. The sternal area is provided with 7 — 9 very 

 narrow fenestras and with a broad crj'ptocyst lamina, while each lateral surface 

 is occupied by two large lateral chambers separated by an angulated ridge. The 

 covering kenozooecium distally to the aperture on either side has a very irregular, 

 transversely oval or bean-shaped, often more or less sharply sinuated or lobed 

 uncalcifled portion with a cryptocyst depression in its marginal portion. On its 

 surface we find 6 — 10 chambers of most variable form, which are covered by a 

 membranous roof and bounded only by low ridges. Distally to and outside the two 

 uncalcifled areas there is on both sides eitljer one very long and rounded or two 

 adjacent chambers, a larger and a smaller one. On the basal side of the ooecium 

 we find three, a smaller unpaired one proximally and two adjacent ones distally, 

 the proximal half of which may sometimes be provided with a separating ridge. 

 On the frontal side of this group we find again a separate one ending in a very 

 thin point (figs. 1 b, 1 e), while its basal part has two bulgings which may be 

 separated as independent chambers. 



Form of colony. We may find rows of up to 5 single zocecia springing from 

 a daughter-zooecium, but otherwise the alternation of uni- and bi-zocecial inter- 

 nodes is regular. 



Of this species I have examined a colony from Port Phillip Heads (Miss 

 Jelly). 



