ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
435 
outside the one last formed that the edge of the corallum grows out- 
wards into an ever-expanding cup or disc. The author next describes 
the flowing of the coenenchyma and the thickening of the cup. This 
results frequently in filling up the bottom of the cup, when all the 
polyps which formed the cup at its younger stages are completely sub- 
merged. Outside it streams down over the stalk, not only thickening 
it, but expanding its base of attachment. The two typical elements of 
increase in the growth of the corallum are therefore, typical budding, 
and the flow of material building up the coenenchyma. In addition to 
this, nearly all Turbinarian coralla with uneven surfaces seem to have 
the coenenchyma accumulating in the valleys, as it does in the bottom 
of the early cups. The author has distinguished eight principal 
growth-forms among the Turbinarians in the collection of the British 
Museum. These he distinguishes by the following terms : — Crateri- 
form, Peltate, Frondens, Foliate, Mesenteriform, Tabulate, Glomerate, 
and Bifrontal, but it is not to be supposed that these definite types 
exhaust the possible transformations of the early cup. When our col- 
lections are more complete other normal methods of growth will no 
doubt have to be added. With regard to the taxonomic characters sup- 
plied by the calicles, those which appear to be of the most importance 
are — the characters of the protuberant calicles ; the character of the 
septa ; the interseptal loculi ; and the columella. The influence of 
position on the character of the calicles opens up a great field for in- 
vestigation. As the coenenchyma is very prominent in Turbinaria it, 
too, may offer characters of specific importance. Certainly the fineness 
or the coarseness of the texture has a certain value. It is of interest to 
note that the general aspect of the coenenchyma seems to vary with 
geographical position. There are groups of specimens from various 
parts of the world, evidently collected at the same time, and from nearly 
the same spot. In each case, all the specimens of these groups look at 
first sight strangely alike. So strong is the likeness between the speci- 
mens in each case, that, without some definite principles of classification, 
one could hardly avoid lumping them all together. 
Actiniae of ‘ Albatross ’ Expedition.* — Prof. J. Playfair McMurrich 
has an extended account of the Actiniae collected by the ‘Albatross’ 
during the winter of 1887—8. After a critical account of the classifica- 
tion of the Anthozoa, and especially the Actiniae (in which he recognises 
the following tribes : — (1) Rugosae ; (2) Antipatharia ; (3) Alcyonaria ; 
(4) Edwardsiae; (5) Ceriantheae; (6) Zoantheae; (7) Protactiniae ; and 
(8) Hexactiniae ; and for which he proposes a fresh classification based 
primarily on whether the tentacles are arranged in cycles or radially) he 
proceeds to an account of the specimens collected. Of the genus 
Edwardsia a new species, E. intermedia , was found, represented by a 
single specimen. In the Protactiniae a new genus Oractis is proposed 
for the forms with twenty mesenteries. In the Halcampidae a new genus 
Halcurias is formed for H. pilatus In the Antheidae, Myonanthus 
ambiguus is a new type remarkable for its power of completely retracting 
the tentacles. PycnantJius is a Paractid unlike any of the present known 
genera, while Cymbactis is remarkable for the absence of any thickening 
* Proc. U.S. Nat. Mus., xvi. (1894) pp. 119-216 (17 pis.). 
