322 



in most zooecia they are further more or less nodulous or lobate or even more 

 or less deeply divided. 



The ooecia, which are strongly arched and not rarely provided with one or 

 several tubercle-like projections, show as a rule a narrow depressed margin im- 

 mediately distally to the aperture, caused apparently by the thickening layers 

 not reaching quite so far down. 



The avicularia, which are placed nearer to the aperture than in the two 

 species above described and in which the mandible points obliquely distally and 

 outwards, appear sometimes double sometimes singly. 



A small colony from Port Western, Victoria (Dr. Harmer). 



Exochella Zelanica n. sp. 



Mucronella diaphana, forma armata Hincks, Annals Nat. Hist. ser. 5, 

 Vol. X, p. 167, PI. VIII, fig. 3. 

 (PI. XVir, figs. 8 a— e). 



The zooecia hexagonal, rhombic, thick, rather strongly arched, provided with 

 small scattered pores and with 3 — 4 oral spines. They are surrounded by a 

 strongly developed raised line which in the same manner as in Escharella dia- 

 phana may be partly coalesced with the lateral parts of the frontal wall and often 

 has a freely projecting undulating edge (fig. 8 c). There are 6 — 7 marginal pores. 



The peristome is only developed proximally and of the two sets of teeth 

 the inner has a somewhat similar form as in the foregoing species, whilst the 

 strongly projecting and prominent, central tooth of the outer set is large and 

 broad, quadrangular or trapeziform, coalesced along its frontal surface with a 

 somewhat narrower thickening of similar form. 



The ooecia, which were not found on Jhe colony examined, are according to 

 Hincks provided with a thickened middle part. 



The avicularia may occur both in pairs and singly, but their position and 

 direction seem to undergo more variation than in the previous species. 



I have seen a very small colony of this species, found on an Alga from the 

 Akaroa Harbour, New Zealand; depth 6 fathoms. 



Genus Schizoporella Hincks, char, emend. 

 Spines may appear. The aperture with a faintly developed vestibular arch and 

 with a well-developed sinus, which may vary greatly both in depth and breadth. 

 The operculum well-chitinized, with muscular dots. The zocecia with scattered 

 pores and as a rule with a small projection proximally to the aperture. An avi- 

 cularium may occur on each side, but in more or fewer zooecia the one or both 



