7. Anthozoa (incl. Hydrocorallia). A. Zoantharia. 21 



probable for deep-sea species. The similarity of the polar Actinian faunae is 

 a negative character, and is due less to the common possession of certain forms 

 thaii to the absence of a number of groups characteristic of other seas; some 

 resemblances, e. g. the presence of brood pouches, are due to convergence. 

 The geographical distribution of the Actiniae affords no support to the pendu- 

 lation theory. - The author has examined the original specimen of Palaactis 

 vetula and concludes that it is not a fossil Actinian, but of inorganic nature. 

 The species of Stichodactylinse of the West Indies and Pacific may be con- 

 sidered as races of the same species; this family has probably undergone no 

 further evolution since tertiary times. The three Anthozoan groups have di- 

 verged from a common root; the common ancestor of the Cerianthids and 

 Antipatharia was probably colonial. The Actiniacea and Zoanthacea may have 

 had a common octo-radiate ancestor, most nearly represented, among living 

 forms, by the Halcampula larva. The Zoanthacea (to which the Rugosa are 

 nearly related) and Actiniacea diverged later, the former remaining colonial, 

 the latter becoming solitary. The Madreporaria are represented as branching 

 off the stem near the Stichodactylinae, which present numerous affinities to the 

 corals, e. g., the occurrence of examples of Eic. florida with several mouths 

 (cf. Manicina and Mycedium), the basal coenenchymatous connection in Cory- 

 nactis viridis, the knobbed tentacles of Coryn. and Corallimorphus and their 

 division into marginal and oral series (cf. Caryopkyllia), the position and 

 arrangement of mesenteries, and the mesenterial filaments of Coryn., Ric. and 

 Actinothryx which have, like those of corals, only a median glandular streak. 



Pax( 3 ) regards Palceactis vetula, which was described as a fossil Actinian 

 by Dollfus (1875), as being probably an inorganic formation. The Pacific 

 elements in the Actinian fauna of the West Indies, especially Asteractis, Phy- 

 manthuS) Actinothryx, Stoichactis, Ricordea and Isaurus, are due to the former 

 continuity of the Pacific and West Indian regions, previous to the elevation of 

 Central America, which took place in a quite recent period (Pliocene). The 

 high degree of specialisation which Actiniae had attained in tertiary times, and 

 their slow development during this period, indicate that these animals are an- 

 cient. Perhaps they had their origin as far back even as palaeozoic times. 



Hargitt( 3 ) describes Cradactis variabilis n., from the Tortugas. The most 

 remarkable feature is the presence of peculiar frond-like organs just outside 

 the outer cycle of tentacles. There are usually 6 of these organs, more or 

 less symmetrically arranged; each is dichotomously forked once or twice, and 

 the tips are knobbed. On the upper surface of these organs there is usually 

 a whitish glandular disc or pad, which is provided with large nematocysts. 

 These organs may aid the Actinian in its movements or in capturing its prey. 

 McClendon states that Crad. var. is kept just within the mouths of the 

 cavities in reef-rocks in which it lives by the combined action of the negative 

 heliotropism of its base and of the positive heliotropism of its fronds. These 

 possess the sense of taste but do not carry food to the mouth. They are 

 lures, or serve to hide the Actinian from its prey; they are heliotropic and 

 contract completely at night. C. v. is viviparous. The first pair of fronds 

 appears, when the young anemone has 20 tentacles, as outgrowths of the body- 

 wall just beneath the tentacles. C. v. moves from place to place by walking 

 on its tentacles. 



Lager describes, from south-west Australia Boloceroides 1, Cystiactis 1, 

 Saccactis n. (Phyllactidae) 3 n. sp., and 1 n. var., Isactmia 1 n., Gyrostoma 2 n., 

 Cribrina 2 n., Phymanthus 1, Stoichactis 3 n., Antheopsis 2 n., Stichodactis 2 n. 

 In the uppermost part of the column of Sacc. there occur more or less branched 



