382 Transactions. 



are not completely retractile. The ectoderm and endoderm are thick and 

 the mesogloea thin. The musculature is very weak. 



Orcd Disc. — The colour is brownish-green. The mouth is set on a slight 

 elevation, from which radiate yellowish lines. The structure of the disc 

 closely resembles that of the tentacles. 



Stomodceum. — This is pinkish-white in colour, and there are 2 siphono- 

 glyphs. In cross-section the stomodseum is seen to be strongly folded. 



Sphincter. — Weak, endodermal. Its shape in cross-section is semi-ovate,, 

 the flattened side closely appHed to the body-wall. 



'Mesenteries. — There are 24 pairs, every second pair being perfect. Two 

 pairs are directives. The musculature is strong, especially on the perfect 

 mesenteries. The muscle-banners extend almost from wall to stomodaeum^ 



Gonads. — None seen in my specimens. 



Size. — Diameter, about 20 mm. ; height, rather less. 



Habits. — This species is found in rock-pools, often inhabiting quite small 

 " pot-holes " on the upper part of the rocks. Its colour is strongly pro- 

 tective. 



Distribution. — Of the genus — English Channel, Atlantic, Mediterranean,, 

 Patagonia, Torres Strait, Pichelingue Bay (Delage and Herouard) ; also 

 New Zealand. Of the species — Dunedin (Hutton), Cook Strait. 



Fam. SAGARTID.E. 



" Hexactinim furnished with acontia." 



In thus defining the Sagartidce I have followed what seems to be the- 

 general tendency of recent authors. Hadden has somewhat fully discussed 

 the classification of sagartians, though he arrived at no very definite con- 

 clusion. In using the term " sagartians " he says, " By the latter term I 

 include all those Actiniw which possess acontife." McMurrich (" Albatross " 

 Report, 1893) says, " It seems at present convenient to associate all Actinice 

 with acontia in a single family." Most authors, however, in defining the 

 family still include the provision " sphincter muscle mesogloeal." I shoiild 

 like to point out, on the authority of G. C. Bourne, that Actinoloba, a sagartian 

 genus, has an endodermal sphincter. 



Subfam. SAGARTIN.E. 

 " Sagartidce with naked ectoderm. Cinclides usually preSent." 



Genus Sagartia (Gosse). 

 " Sagartidce with smooth column ; no verrucae ; no special arrangement 

 of cinclides ; margin tentaculate ; tentacles concealed in contraction, the 

 sphincter being fairly strong " (McMurrich). 



5. Sagartia albocincta (nom. nov.), Hutton. 



A description of this species is published at p. 372 of this volume. 



Distribution. — Of the genus — Arctic Ocean, North Sea, Enghsh Channel, 

 Atlantic, Mediterranean, Cape Horn, Pacific coast of South America, East 

 Indies, Australia (Delage and Herouard) ; also New Zealand. Of the 

 species — Dunedin (Hutton), Plimmerton (H. B. Kirk), Cook Strait. 



6. Sagartia nutrix (sp. nov.). 



This is the brown sagartian mentioned by Farquhar as probably forming 

 the food of the butter-fish. It is found only on Lessonia, where it establishes 

 itself in colonies. 



