ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 55 



has yet given. New methods must be found for our attempts to 

 explain how the Beroe can thus shift its position," 



Zoantharia of the Gulf of Marseilles.* — After shortly describing 

 the local distribution of the chief Zoantharian forms in this district, 

 M. E. Jourdan proceeds to deal with their zoology, histology, and 

 development. 



Under the first heading, besides many well-known British species, 

 there is described a species without chromatophores, and therefore 

 assigned to the genus Paractis as probably identical with Actinia 

 striata of Risso ; also a Sagartia new to science (S. Penoti), occurring 

 either small in size and dull in colours, or large and brightly tinted. 

 The well-known Sagartia parasitica is referred to Actinia effceta Linne, 

 under the generic name Galliactis Verrill. Phellia (Actinia) elongata 

 Delia Chiaje, appears to have been recently found also in Dalmatia. 

 Hyanthus Mazeli is described as new, from 60 to 80 metres depth. 

 Palythoa axinellce is found on Algae as well as on sponges ; a new 

 species (P. Marioni) of the same genus is described, from sponges 

 and Serpula-tubes, from a depth of 110 metres ; the columns are from 

 15 to 18 mm. high ; colonies consist of but three or four individuals 

 each, they are transparent, and of a very pale rose-colour. No 

 Edivardsia occurred. Of sclerodermic corals were obtained Caryo- 

 phyllia clavus, Paracyatlms pulcJiellus, Flahellum anthophyllum, Clado- 

 cera ccespitosa, Balanophyllia italica and regia. 



In the second part [Histology) the methods of study are stated to 

 have been : (1) Observation of the living tissues : this was found 

 especially useful | in distinguishing cilia from cnidocils. (2) Immer- 

 sion in i per cent, osmic acid followed by absolute alcohol was found 

 on the whole the best plan for hardening ; hardening in osmic acid alone 

 and mounting in glycerine were also found effective. Weak chromic 

 acid solution or chromic and osmic acids mixed (Fleisch's recipe) were 

 successfully applied to the hardening of small pieces by their immer- 

 sion in them for two or three days. Larvee were treated somewhat 

 similarly. Picrocarmine and hsematoxylin were found the best 

 staining fluids. (3) Dissociation, for which a month's maceration in 

 a i per cent, solution of ammonia bichromate, or in very weak solu- 

 tions of chromic acid, was a good preliminary step. Sclerodermic 

 corals were first decalcified with picric acid. 



The results thus discovered in various species are as follows : — 



Anemonia sulcata [Anthea cereus of Gosse). — The tentacles have a 

 slightly striated ectoderm, in which no distinct layers were made out, 

 but when hardened it is found to be covered externally by a layer 

 formed of the cilia agglutinated by mucus ; at its true surface lies a 

 layer of thread-cells, which sometimes occur without the coiled thread ; 

 similar cells occur deep in the layer. The thread-cell originates 

 in a small, generally oval, cell provided with a basal prolongation ; 

 it appears first as a small rod lying beside a large nucleus among 

 the granular protoplasm ; it ultimately comes to be the only thing 



* Ann. Sci. Nat , x. (1880) Article No. 1, 154 pp. (17 pis.), 

 t Cf. a contrary opinion, this Journal, iii. (1880) p. 451. 



