260 PERCY SLADEN TRUST EXPEDITION. 
axial furrow has become broken up into a series of centres, its single species, C. talpina, 
in the arrangement of its calicles being connected by Herpolitha crassa to H. limax, the 
type species of its genus. It, however, shows a distinct gap in other characters, 
particularly those of its costee and septa. In addition to my own specimens of C. talpina 
mentioned below, I have examined five specimens in the British Museum ranging up to 
42 em. in length. These show clearly that the younger the specimen the more distinct 
are its secondary axial centres and its subsidiary side calicles, radiation of septa from 
them being clearer. This is not the case in Herpolitha, some specimens of which show 
almost the opposite character *, so that I must regard Cryptabacia talpina as the type of 
a good genus. 
Polyphyllia was founded by Quoy and Gaimard ¢ for a species, P. pelvis, from New 
Ireland. Their description was inadequate, but the type was redescribed and figured by 
Milne-Edwards and Haime{. The specimens were of large size, 20 to 30 em. long by 
7 to 10 em. broad. In the British Museum I found three specimens labelled P. pelvis, 
one of them so named by Briiggemann coming from “Swan River, Australia,” and two 
older specimens from unknown localities. All were over 33 cm. in length, but when. 
examined were clearly large specimens of Cryptabacia talpina, having both the central 
and side calicular centres less distinct, 7. e. septa less radiating, than in smaller specimens 
of the same species, a regular age and size character in that species. At the same time 
all three specimens examined by themselves would be regarded as typical Polyphyllia, 
resembling in every respect Milne-Edwards and Haime’s description of the genus. 
Further, its type species, P. pelvis, seems to me to be identical with Cryptabacia talpina. 
The arrangement of septa shown in Milne-Edwards and Haime’s figure 1 d is quite 
typical of that species, the individual septa between the moath-openings being better 
shown in their fig. le. Generally the septa of the second series are not perhaps so thick 
and distinct as in 1d, but there is one specimen in the British Museum from 
“W. Island, Torres Straits,” which has still thicker septa of the smaller series, having a 
similar surface appearance and rising higher than usual in relation to the septa of the 
larger series, so that the connections of the latter septa to the corners of the elongated 
meshwork of the second series (shown in fig. 1 e) is quite indistinct from surface view. 
Lastly, the details of the surface structure of the costz and septa are of precisely the 
same character in the two species. Obviously both species must be referred to the same 
genus, and Cryptabacia becomes a synonym of Polyphyllia. 
Lithactinia is merely a rounded form of the last, with no suggestion of an axial furrow 
broken up into calicular centres. A species, L. nove-hibernie, was first described and 
figured by Lesson § on a single small specimen, but the figures might well represent a 
part of a corallum of a species of Polyphyllia. Milne-Edwards and Haime || redescribed 
the species but published no figure; and indeed no figure has since been published. 
Furthermore there is no adequate figure of any other specimen supposed to belong to 
* The specimens of /7, limax in the British Museum on which I base this observation may possibly belong to two 
species, but they seem to make one series. 
+ Voyage de l’Astrolabe, Zooph. p. 185, pl. xx. figs. 8, 10 (1833), 
+ Cor. ii. p. 26, pl. D 11. fig. 1, a-e (1860). 
§ Iustr. Zool. pl. vi. and Description (1831). || Cor. iii. p. 28 (1860). 
