8. Abstammungslehre. 481 



1319) Herdmali, W. A. (Liverpool University), A comparison of the 

 summer plankton on the west Coast of Scotland with that of the 

 Irish Sea. 



fJourn. Linnaean Soc. Zoology 32,211. p. 23— 38. 1911.) 



Doncaster (Cambridge). 



1320) Hicksoil, S. J., On Ceratopora, the type of a new family of 

 Alcyonaria. 



(Proc. Roy. Soc. B84,B570. p. 195—200. 1911.) 



Doncaster (Cambridge). 



1321) Kirkpatrick, R., On Merlia normani, a sponge with a Sili- 

 ceous and Calcareous Skeleton. 



(Quart. Journ. Micr. Sc. 56,4. p. 657— 702. 7 plates. 1911.) 

 Merlia normani is a sponge having the remarkable peculiarity of 

 possessing both siliceous spicules and a solid calcareous skeleton. This has 

 been disputed, some writers regarding it as a calcareous organism of unknown 

 nature covered superficially by a siliceous sponge. The author however re- 

 gards this view as in admissible, and gives evidence which he considers con- 

 clusive of the organic unity of the two parts. The sponge was dredged in 

 large numbers off Porto Santo near Madeira. It is a red encrusting organism, 

 usually of small size, with numerous oscula surrounded by inhalent pores. 

 It consists of an upper layer containing siliceous spicules and the canal 

 System, and a lower layer supported by the remarkable calcareous skeleton, 

 but these two layers are in perfect continuity. The canal System is of a 

 peculiar type, the flagellated Chambers being hemispherical, covered on the 

 Hat side by a membrane in which is the apopyle. The prosopyles are small 

 spaces between the collar-cells. The siliceous spicules are of five kinds, the 

 most frequent being pin-shaped („tylostyles"). The lower part of the sponge 

 consists of „crypts" placed in vertical series three or four deep, each series 

 being enclosed in a calcareous tube secreted by the crypt cells, and the crypts 

 of each vertical series are partially separated by incomplete horizontal tabulae 

 crossing the tubes. The tubes are made up of calcareous columns, each with 

 three vertical wings which unite with the wings of neighbouring columns to 

 form tubes. That the organism is simple, and not a siliceous sponge over- 

 lying a calcareous organism of different nature, is indicated not only by the 

 continuity of structure in the adult, but also by the structure of the growing 

 edges and by very young specimens, in which the early stages of the deve- 

 lopment of the calcareous skeleton can be traced. The author regards Merlia 

 as a siliceous sponge which has taken to depositing a calcarous skeleton at 

 its base, and essentially outside its tissues, possibly originally by way of excre- 

 ting superfluous lime ingested by its cells, but later as an adaptation for 

 support and protection. Doncaster (Cambridge). 



1322) Gravier, Ch., Les recifs de Coraux et les Madreporaires de 



la baie de Tadjourah. 



(Annales de l'Institut Oceanographique 2,3. 104 pp. 6 fig. dans le texte, 3 cartes hors 



texte et 12 planches en höliograv. 1911.) 



Ce tres beau memoire, fort luxueusement edite, est consacre k l'etude des 

 Coraux que M. Ch. Gravier a lui-meme recueillis dans la mer Rouge. La 

 premiere partie traite de la position geographique des recifs et de leur bio- 

 logie; la seconde partie, entierement systematique, est devolue ä la description 

 des especes. 



Les recherches de l'auteur ont surtout porte sur la baie de Tadjourah, 

 dependance du golfe d'Aden. Presque tous les recifs de cette rcgion — sauf 



