KUNGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 59. N:0 I. 17 



Herpolitha simplex Gardiner 1905. 



Herpolitha simplex Gardiner 1905 (14). p. 943, plate XCI, fig. 13. 



One specimen from Broome. 



Length 15 cm; greatest breadth 4,9 cm in centre of corallum; gréatest height (not 

 thickness) 2,1 cm, likewise in centre. The specimen, however, is somewhat deformed 

 in the centre, owing to a triangulär piece at one side of the corallum, where it has been 

 damaged and has died; then the intact parts around ha ve secreted a calcareous crust 

 with septal structure, and this crust delimits the dead piece. The central fossa, which 

 has a breadth of 1,5 — 2 mm and a depth up to 8 mm, and extends över the whole corallum, 

 is divided into two parts by means of that deformation. Close to the deformation and 

 on either side of it there is a septal fusion across the fossa; but in other places the 

 fossa is not broken up, though an indication of an incipient fusion is to be seen on 

 two other places, one on each side of the middle. 



The specimen, the under surface of which does not show any scar of attachment, 

 agrees perfectlv with the figure and the description by Gardiner in regard to the co- 

 lumella, the septa, the appearance of the under surface, and the theca. 



Polyphyllia producta Folkeson n. sp. (Figs. 25 — 26). 



45 miles W.S.W. off Cape Jaubert, 1 ap. 



The breadth of the specimen, which is to be seen on the photograph, is remark- 

 ably constant; the height is verv diminutive in relation to the length of the corallum. 

 The underside is almost flat in the centre, but concave (up to 8 mm) towards the ends; 

 it is sparingly perforated and is covered with strongly granulated, low spines or short 

 keels, which are not at all radiating, except near the margin. At the curved part of 

 the corallum there is an indication of a detachment scar in the form of a påle rusty 

 brown elevation, which lacks the spines. 



The axial fossa is divided up by septal fusions into 46 secondary calices, each 

 with 17—20 radiating septa, of which the larger ones at least reach the columella; the 

 latter is formed by aggregated septal processes and is distinct, though narrow and little 

 developed. The median range of calices is verv marked, owing to the crowded ar- 

 rangement of the septa (15 — 18 per 1 cm) and to the thickness of the septal fusions. 

 On the whole, the corallum looks more dense than the specimens photographed by 

 Gardiner (15). The lateral calices are arranged in suites, more or less pronounced. 



Septa of two kinds. The higher ones are thick, strongly granulated, and crenel- 

 ated: the septa of the central calices average 4 — 5 mm in length, the septa of the 

 margins of the corallum 7 — 10 mm, the length of the rest 2,5 — 4 mm. The higher septa 

 exceed the lower ones 0,5 — 1 mm onlv; the latter are thinner and not so distinctly granul- 

 ated; with the exception of the margin of the corallum, the lower septa every where 

 form the meshwork characteristic of the genus. 



According to the degree of radiation of the septa, and to the presence or absence 

 of a central furrow broken up into calices, the three genera. Cryplabacia, Polyphyllia 

 and Lithactinia were established. In Cryptabacio, all septa of all calices are more or less 



K. Sv. Vet. Akad. Handl. Band 59. N:o \. 3 



