32 Coelenterata. 



no such apertures and was therefore isolated from its neighbours, except, of 

 course, at the stolon; others had, according to their size, 2, 3, 4, 6 or 10 

 apertures in their wall. Production of secondary polyps is preceded by formation 

 at the point of budding (buds are formed only from the 2 dorso-lateral chambers) 

 of a meshwork of endodermic canals in the mesoglcea of the primary polyp. 

 At the base of the secondary polyps there are small apertures opening into 

 the coelentera of the primary polyps from which they have budded. Endodermic 

 canals are well developed in the stolon and there are longitudinal canals in 

 the inter-polypal partitions which, however, do not bear transverse branches 

 opening into the coelentera. Par. passes through a stage which corresponds 

 to the adult Fasc., but afterwards the former is distinguished by coalescence 

 of its polyps above the basilar portion and by formation of secondary polyps 

 as above described. Par. is oviparous but the authors also found numerous 

 planulre in the coelentera. The morula rapidly becomes a blastula and a 

 ciliated larva which, when only 1 mm. long, becomes transformed into a young 

 polyp, either before or after fixation. Some free swimming individuals show 

 traces of tentacles and have 8 complete mesenteries. F. and P. are most nearly 

 related to the family Organidse (and especially to Organidus] and also have 

 affinities, especially through F., with Clavularidse. The family Fascicularidse 

 (for F. and P.) should however be preserved; its diagnosis is given thus colonies 

 very poor in cceneuchyme, composed of several groups of polyps united by a 

 stolon, polyps fused at the base into a rigid column into which they may 

 completely retract. 



Gravier( 2 ) describes two forms of unicellular algse in the tissues of Sarco- 

 phytum mycetoides. There are spherules, 8 /< in diameter, with hyaline proto- 

 plasm, in the autozooids and they are especially abundant in the tentacles, 

 forming, in the neighbourhood of the upper surface, an almost continuous layer. 

 They also penetrate into the endoderm. Opaque, granular, dark yellow, elongate 

 algae are found in the mesoderm forming irregular, often anastomosing, tracts. 

 Some of these cells are in course of division. The author suggests that these 

 feed on the mesoderm of their host, being away from the influence of light 

 and unable to form their own food material. The "ovule" is invaded by these 

 algai before it separates from the mesentery on which it has been formed. 

 When the mesoderm has been developed, the alg<e leave the endodermic capsule 

 in which they have so long remained, penetrate into the mesoderm and there 

 multiply. Later from these spores are formed the spherical zoochlorellse which 

 are found in the upper parts of the colony. The alga seems to have two 

 stages : the first is parasitic in the mesoderm and the second lives in the surface 

 portion of the colony and not only provides its own food but contributes to 

 that of the colony. - See also Gravier( 7 , 9 , lu ). 



Kiikenthal^) gives revised diagnoses of Gersemia and Eunepkthya. Those 

 Nephthyidati [s. Bericht f. 1905 Coel. p 27] whose polyps are without "Stiitz- 

 btindel", whose canal walls are thin and not closely packed with spicules and 

 whose polyps occur singly or in bundles, belong to G. and E. G. is distin- 

 guished by its polyps being divisible into an upper retractile part and a lower 

 calicular part into which the upper part can be withdrawn. In E. the polyps 

 do not exhibit this differentiation- and are either completely or not at all re- 

 tractile. The headquarters of G. are the cold northern seas from which single 

 species have spread into the Atlantic and Pacific Oceans. The species (of 

 which 8 are described) are either deep littoral or from the deep sea. E. is 

 divided into two groups - - (1) Alcyoniformes (8 sp., 1 n. var.), in which the 

 ends of the branches are thick and contractile, the polyps solitary, cylindrical, 



