7. Antkozoa (incl. Hydrocorallia). A. Zoantharia. 17 



Duerden( 7 ) describes the anatomy and histology of Bunodeopsis globulifera 

 and shows that while possessing several primitive Actinian characters it is in 

 other respects highly differentiated. Among the former may be reckoned the 

 occurrence of an ectodermal columnar and stomoda^al muscle- und nerve-layer, 

 the absence of gonidial grooves from the stomodieum, the absence of a basilar 

 muscle and the weakness of the internal musculature. On the other hand it 

 is differentiated in that the column is divided into two distinct regions of which 

 the upper is naked and the lower bears hollow evaginatious, the ectoderm of 

 which is thickened and bears numerous thick-walled nernatocysts ; there is a 

 teutaculo-coelomic septum provided with a sphincter muscle; the circunioral 

 ectodermal thickening (lips) is charged with thin-walled nernatocysts; and there 

 is a circunioral endoderrnal sphincter. 



Duerden( 8 ) describes the Actinians of Porto Rico. He gives an account 

 of the present classification of Actiniae pointing out the position of the primary, 

 and the mode of origin of the following, mesenteries. Detailed descriptions 

 are given of Cerianthus 1, Zoanthus 2, Isaurus 1, Palythoa 1, Protopalythoa 1, 

 Asteractis 1, Bunodosoma 2 (1 n.), Aiptasia 1, Calliactis 1, Stoichactis 1 and 

 Phymatnthus 1. A section of a polyp of Z. sociatus is figured which is brachy- 

 cuemic on the left and macrocnemic on the right. A similar condition has 

 been previously recorded in Pal. mammillosa and caribcw, and one polyp of 

 the latter was altogether macrotypic on both sides in place of the normal 

 brachytype. The author rejects the suggestion of Roule [s. Bericht f. 1900 

 Coel. p 11] that Epizoanthus, Parazoanthus and Gemmaria should be merged 

 in Palythoa, as such an association depends on external appearances and habit 

 of the colonies and is not supported by internal structure. 



Me Murrich( 1 ) describes a specimen of Cribrina elegantissima with 3 siphono- 

 glyphs; in a second specimen 2 are present but they are not opposite each 

 other, while in a third only a single siphonoglyph occurs. In each case there 

 is a corresponding number of pairs of directives. The author shows a section 

 of Epiactis prolifera passing through the column wall to which an embryo is 

 attached. This embryo is not a bud but an egg embryo which has become 

 attached to the surface of the adult and is held there by the mucus secreted 

 by the ectodermal gland cells. He also describes the anatomy of Metridium 1, 

 Cribrina 1, Urticina 1, Anthopleura 1. 



Me Murrich( 2 ) makes a further study of Halcurias pilatus and finds short 

 mesenteries in the upper part of the column, which together with the 20 per- 

 fect mesenteries already described are equal in number to the tentacles, 

 viz. 68. The short mesenteries are situated in the endocosls of the perfect 

 mesenteries (except the directives). This arrangement corresponds to that 

 described by Carlgren in Endoccelactis. From this and other characters the 

 author believes that the two forms must be referred to the same genus, to 

 which the prior name H. must be applied. 



Torrey(') reunites Edwardsia and Edwardsiella as they essentially agree in 

 the arrangement of their tentacles and in other respects. The specimen of 

 Edwardsia sipunculoides shows no trace of siphonoglyph while two others have 

 one each, situated ventrally. The author regards E. beautempsi as the only 

 species in which the mesenterial plan fulfils the requirements of an ancestral 

 form. He describes the Halcampid Harenactis n. attenuata n., in which there 

 are 2 pairs of directives but only one siphonoglyph and also a bilaterality of 

 the mesenteries probably correlated in some way with this single siphonoglyph. 

 In discussing variation in Metridium dianthus the author concludes that regular 

 hexamerous diglyphic polyps arise asexually as well as sexually, that mono- 



