7. Anthozoa (incl. Hydrocorallia). A. Zoantharia. 27 



and more elliptical, in a similar situation or near the mesoglcea where they 

 undergo all but the last stages of their development. Nematocysts are more 

 numerous round the mouth. The stornodseum, which has no siphonoglyphs, 

 is about 9 mm. long; its wall contains long slender ciliated cells, less numerous 

 gland cells and few nematocysts of the same size and shape as the larger ones 

 of the general ectoderm. The mesoglosa is relatively thick and is crossed 

 by fusiform cells. The ccelenteron, mesenteries and endoderm are similar to 

 those of 7i. henseni. In both species there are 6 macro- and 6 micro-mesenteries 

 alternating with each other and symmetrically arranged with regard to the 

 dorso-ventral plane. The macro-mesenteries alone meet the stomodteurn, and 

 extend downwards nearly to the aboral pole, their free border bears a non- 

 convoluted filament. Judging from their size the mesenteries arise in the 

 same order as assumed by van Beneden for Z. henseni. - - See also Car!gren( 2 ). 



Me Murrich^) finds in Cerianthus elongatus from Amboina, on each side of 

 the mid-siphonoglyphic line, the usual short sterile directive mesentery , then 

 two additional sterile mesenteries and a long fertile one which extends almost 

 to the aboral pole. The long mesentery is then, in this species, the fourth, 

 and not the second as in all other species examined. 



Me Murrichf 2 ) gives the results of his revision of Duchassaing & Michelotti's 

 Actinian types contained in the Museum of Natural History in Turin : Actinostella 

 formosa, flosculifera , eonchilega and radiata, Lebrunia neglecta, Stoichactis 

 anemone, Ricordea, Orinia, Epicystis crucifera, Zoanthus flos-marimis, sociatus, 

 solanderi, anduzii, dubius and nymphfeus. The species described from the 

 West Indies by Hughes and Hill (1743) and later named Actinia calendula by 

 Ellis & Solander (1786) and two species describe! by Hill (1752) are probably 

 tubicolous annelids. 



Roule( 1 ) describes SticUopathes 4, Antipathes 2 (+ 1?), Antipathella 1 (+ 1?), 

 Paratylopathes (n. subg. of Tylopathes) 2, Leiopathes 1, Parantipathes 1, Bathy- 

 pathes 1, Aphanipathcs? 2, Cerianthus 2 (1 n.), and gives a comparative account 

 of the anatomy and histology of the group. The axis is secreted by ecto- 

 derm, as in Gorgonids, and becomes enveloped by the bases of the polyps 

 which form it. S. dissimilis and Paraty. grayi have dimorphic polyps of two 

 different sizes which alternate; a similar condition is seen, but less clearly, in 

 Leiop. glaberrima. The histology (nature of the mesogloea, absence of muscle 

 ridges on the mesenteries, simple structure of endoderm) of the Antipatharia 

 supports their relationship to the Cerianthidse. Antipatharia are simple and 

 primitive, not degenerate, as is indicated by their stornodtieum without siphono- 

 glyph, their rnesogloea and musculature; there is no trace of a differentiated 

 rnesogloea or of a mesenterial musculature to suggest that they are descended 

 from more highly organised ancestors. The author includes the Antipatharia, 

 the Cerianthidse and the Tetracorallia in one group - the Protanthozoa 

 (6 principal and some complementary mesenteries, column without musculature 

 except longitudinal ectoderrnal fibres, mesenterial musculature absent or feeble 

 and diffuse). The Ctenophores belong to the same series as the Anthozoa 

 and Scyphozoa, and a phylum - - "Scyphozoaires" - is formed to include these 

 three groups. The Antipatharia were primitively solitary and the ancestral 

 form was not unlike the Cerinula - - the young Cerianthid larva - - having 

 the Anthozoan organisation in its most elementary condition. Such an ancestral 

 form may be considered as being common to all the Anthozoa and to have 

 differed little from the ancestral Scyphozoon except that the latter had two 

 fewer mesenteries. In the Anthozoa the two lateral mesenteries become 

 duplicated possibly in correlation with the elongation of the stomodieum. Colonial 



Zool. Jahresbericht. 1906. Coelenterata. e 



