On a new species of DESMOPHYLLIDI (D. quinarium) and a young stage of CYCLOSERIS SINENSIS.
BY REV. J. E. TENISON-WOODS, F.L.S., F.G.S., Cor. Memb. Linn. Soc.
page 17
Desmophyllum is a genus of Turbinolinae, which is specially distinguished by the presence of an epitheca and the absence of a columella; the corallum is simple, generally fixed by a large base; the fosette is very deep, and the septa are very much exserted, and stretch out like huge wings; the last cycle is more developed than that which precedes, and are often united to their neighbours, of the higher orders, from which they slightly diverge as they approach the centre; the wall is bare, smooth below, and presents some little crests in the neighbourhood of the calm. The genus was originally established by Ehrenberg for a species
page 18
of Madrepora of Esper. There are six species enumerated by Messrs. Ed. and Haime, viz., D. cristagalli, Ebenb., D. Cumingi, E. and H., D. costatum, D. dianthus, Esper., D ? Stokesii, E. and H., and D. taurinense, Michelin. The latter is fossil. Prof. Duncan has reduced the four first to mere varieties of one species, for which he retains the name of D. cristagalli, though it seems as if Esper's name (D. dianthus) should be the one selected, as it has long priority (1797). The same author regards D. Stokesii as an immature form of the other varieties. He says (Madre-poraria of the deep sea; Trans. Zool. Soc. vol. 8, 1873, p. 321)." If the variations of the typical form of this species are studied, it will be noticed that there are great difference in the position, size, and continuance of the costae, in the exsertness and granulation of the septa, in the height, compressedness, and size of the base of the corallum, and in the granular ornamentation of the outside of the wall in different specimens. The size, costal developement and granular condition of the ornamentation of the septa, and outside of the corallum, depend upon the age and nutrition of the specimen. Very thin septa are not so granular superiorly as those of corals, which have very thick walls, and dense septa, and the costae of the latter kind are usually most prominent. At great depths, and where the Madreporaria appear to be very abundant, the specimens of Desmophyllum are usually very granular externally, moreover they become attached to compound forms of corals, and both have the same ornamentation, so that it is difficult not to believe in the Desmophyllum being part and parcel of the growing mass. One specimen is attached partly to broken specimens of dwarfed variety, with a small calice, and without costae. Other forms are finely pedunculate " (loc. cit).
I bring this character of variability prominently forward, so that it may be seen what claims the present species has to be regarded as distinct.
DESMOPHYLLUM QUINARIUM, N.S.
Corallum much depressed, narrowed very slightly at the base, and twisted; epitheca, coarse and irregular, with the costae
page 19
appearing like somewhat sharp keels or ridges; but in the only specimen seen by me, the base is so incrusted with calareous algae in thin lamellae, that very little can be seen below the edge of the calicular margin; calice, subpentagonal, but irregular; septa, very high and falcate, concentrically undulately striate, in five systems of three cycles, with the rudiments of a fourth; secondaries, thin in long arched lobes, which very much overhang the edge of the calice; primaries, tall and straight, not exsert, but reaching more towards the centre of the fossa than any others; tertiaries, small, thin, nearly as much exsert as the secondaries, and inclined or curved towards each other outside the wall; fourth order present in two systems only as thin short exsert lamellae; tubercles representing a fifth order in one system; fossa deep and narrow; wall thick and indented inwards by the side of the primaries. Alt. 10, width from the extreme ends of the secondary septal lobes 15 mill. Fiji 20 fathoms, from a bay near Levuka, Dr. Rayner. In the Macleayan Museum.
From the incomplete character of the septa, on which few or no granules are visible, it is evident that this is only a young, specimen. There is, however, nothing in the coral to give rise to the suspicion that the quinary arrangement is due to abortion. The form is peculiar and exceedingly interesting, and no doubt when other specimens are found, the characters of the adult will modify some of the characters which are now described.
Family FUNGIDAE, Sub. Fam. LOPHOSERINAE. Genus CYCLOSERIS.
This genus, which in addition to living species, extends as far as the cretaceous rocks as a fossil, is represented at present by C. cyclolites, and C. hexagonalis, and C. sinensis on the Barrier reef of north eastern Australia. Only the first has hitherto been regarded as Australian. They are small corals, like mushrooms, distinguished from Fungia by the wall being neither perforate nor hispid. In Cycloseris there is no epitheca. In C. cyclolites the disk is very high in proportion to its diameter; in C. hexagonalis it is extremely thin, larger than the last, and hexagonal in the young stage. C. sinensis is three times as thick as the last, though nearly as large. I doubt very much whether the two species can be separated. They have both from 7 to 8
page 20
cycles, and are common on the coral rocks, and in sandy places at from 10 to 20 fathoms. So little is known of the young stages of any of these corals that I think it worth the notice of naturalists to describe a young C. sinensis.
Corallum very small, quite circular, somewhat raised or thick, base not quite flat but sloping very slightly to a circular flattened disk, about half the diameter of the whole; costae very distinct, prominent, in cycles corresponding to the septa, and agreeing in point of size, all very granular, and becoming a mere set of detached granules in the central disk; septa rather thick, projecting beyond the margin, increasing in height to the edge of the fossa, all closely and very prominently granular, and the edges dentate in six systems of five cyles; primaries free to the fossa, and much thicker than the others; tertiaries united to the secondaries at the fossa; fourth and fifth order uniting with the tertiaries about half way; all the orders of the fifth cycle present, but the two last much smaller, and all much serrated at the edge; fossa small, columella represented by a few papillae. Diam. 6, alt. 2 mil. Princess Charlotte's Bay, 10 to 20 fathoms Chevert Expedition.
The flattened disk at the base of the corallum would seem almost like a point of attachment. If the young stage of C. sinensis is pedicellate, it hardly leaves any traces of its existence in the adult state. The specimens under notice were found free, so that the fixed state must belong to a still earlier stage.
Cycloseris sinensis is said by Messrs. Ed. and H. to be a native of the Chinese seas, and there is no mention made of any central disk, which however is found on the lower part of every Australian specimen. I have not been able to compare with any type specimen, so that our Australian examples may after all be a different species. But the similarity is so close in every other respect that I can hardly think this is the case.