790 THE ANIMAL KINGDOM. 



Development of Lucernaria, Korotneff, Z. A. vii. 1884. Young stage of a 

 Charybdaea, Haacke, Z. A. ix. 1886. Egg and Scyphostoma of Nausithoe mar- 

 ginata, Metschnikoff, Embryol. Studien an Medusen, Wien, 1886, pp. 28 and 86; 

 ditto and Strobila of Aurelia and Chrysaora, Glaus, Untersuchungen, &c., and Dk. 

 Akad. Wien, xxxviii. (supra), with lit. cited ; cf. on Aurelia and Cotylorhiza, Gotte, 

 Abhandl. zur Entwickelungsgeschichte der Thiere, pt. iv. 1886 ; and pp. 747-8, ante. 

 Cf. Haeckel, System (supra}, p. 474 ; also von Lendenfeld, Proc. Lin. Soc. N. S. 

 Wales, ix. i&8$,f0r ontogeny of Cyanea Annaskala, p. 275, of Pseudorhiza aurosa, p. 

 293, and Stylorhiza punctata, p. 297. Ontogeny of Pelagia, Krohn, Archiv f. Anat. und 

 Physiol. 1855, p. 491 ; Kowalewsky, in Hoffmann and Schwalbe's Jahresbericht, ii. 

 1873, p. 280; and L. Agassiz, Contributions (supra\ p. 128. Scyphostoma of Rhizo- 

 stoma (=Pi!ema), Glaus, Z. A. iv. 1881, p. 79. 



Medusa in reversed position, Guppy, Nature, xxvii. 1882-83, p. 31 (with ref.) ; 

 Keller on Cassiopeia (supra) ; Id. on Cotylorhiza^ Recueil Zool. Suisse, i. 1 884, 

 p. 405. 



Local colour varieties of Scyphomedusae, von Lendenfeld, A. N. H. (5), xiv. 

 1884. Colouring matter of Jellyfish, McKendrick, Journal of Anat. and Physiol. xv. 

 1 88 1 ; of Rhizostoma (= Cyaneiri), Blanchard, Z. A. vi. 1883 ; Krukenberg, ibid. 

 Zooxanthellae in Cotylorhiza, Keller, Recueil Zool. Suisse, i. 1884, p. 413. 



Locomotor system of Medusae, Romanes, Ph. Tr. 166, 1876; 167, 1877; 171, 

 1880 ; Eimer, Die Medusen physiologisch und morphologisch auf ihr Nervensystem 

 untersucht, Tubingen, 1878. Cf. Wagner, Wirbellosen des Weissen Meeres, 1885, 

 pp. 8 1-2. 



CLASS (?) PORIFERA. 

 (Spongida, Spongiae, Spongiariae). 



Coelenterata of very varied and often inconstant shape ; frequently 

 massive; devoid of tentacles. Concrescence between parts of the same indi- 

 vidual or of different individuals of the same species is very general. The 

 body-wall is perforated by inmimerable minute inhalent pores, and as a rule 

 by one or more larger exhalent apertures the oscula. The epithelia are uni~ 

 laminar , the endoderm cells typically collared and flagellate, or in certain 

 regions only, flattened and either flagellate or non-flagellate. The gastric 

 cavity is (i) simple and either tubular or vasiform ; or (2) tzibular with radial 

 oiitgrowths or cones, a system of inhalent canals more or less complex leading 

 to it, and the tubular central cavity sometimes partially replaced by a system 

 of exhalent canals; or (3) it is represented by sac-like, pyr if or m, or spherical 

 ampullae with inhalent and exhalent canal systems as in (2), the central cavity 

 being as a rule much restricted in extent. Skeletal structures are rarely 

 absent, and consist of either variously shaped spicules hardened by calcite 

 or silica, or of horny spongin fibres with or without siliceous spicules or 

 foreign inclosures. Unisexual or hermaphrodite. The sexual cells are 

 mesoglaeal: the ovum developes into a ciliated larva within the mesoglaea 



