858 APPENDIX. 



muscular layers which are continued into the tentacle. The mouth appears to lead 

 into a very large cavity. No phosphoric properties have been as yet observed. 



A new species of Astasia receives from Kiinstler the name of Astasia costata ; it 

 is distinguished by its ribbed aspect, which is due to the presence in the integument 

 of regular rows of starch-grains ; the digestive apparatus consists of a narrow 

 oesophagus, a large gastric pouch, and an intestine leading to an anal aperture. 



GENUS Proterospongia, S. K. Gr. proteros, earlier; spoggos, sponge. This 

 generic title is herewith substituted for that of Protospongia, employed by the author 

 at Vol. I. p. 363, and which, though not included in either Agassiz' or MarschalPs 

 'Nomenclator Zoologicus,' has, he finds, been preoccupied by Zittel for the 

 distinction of a genus of fossil sponges. 



ORDER Cilio-Flagellata. 



An extensive and highly important memoir relating to that larger section of the 

 Cilio-Flagellata included in this treatise in the family group of the Peridiniidae, has 

 been recently published by R. S. Bergh, of Copenhagen.* In addition to supplying 

 elaborate details concerning the more minute histology and tendency to variation 

 of the many forms already known to science, some half a dozen species are here 

 figured and described for the first time ; no less than three of these being recognized 

 as types of new generic groups. Phylogenetically. Bergh is inclined to accept the 

 genus Prorocentrum rather than Gymnodinium as the stock-form or architype of the 

 Peridiniidae, and further predicates the evolution of the Peritrichous Ciliata through 

 Mesodinium from out of the Cilio-Flagellate order. Evidence that somewhat 

 favours this last-named speculation, but which does not appear to have attracted 

 Bergh's attention, might perhaps be adduced on the grounds that the characteristic 

 oral flagellum of the Peridiniidae finds its homologue in the abnormally prolonged 

 cilium or so-called " soie de Lachmann," developed from the same region in many 

 of the Vorticellidae. 



One important change in the position that has been hitherto allotted to it has, as 

 a result of M. Bergh's recent investigations, to be made in connection with Btitschli's 

 somewhat problematical form Polykrikos Schwartzii, referred provisionally by the 

 author at page 509 to the Holotrichous family Colepidae. As demonstrated by the 

 Copenhagen authority in connection with a closely allied species, Polykrikos 

 auricularis, the generic group must be accepted as a somewhat abnormal Cilio- 

 Flagellate type, differing from the ordinary Peridiniidag in the more abundant 

 development of its ciliary girdles, the oral opening being at the same time sub- 

 terminal. The so-called oral seta, apparently produced in duplicate in the 

 example figured by Biitschli, is clearly shown by Bergh, in connection with P. 

 auricularis, to differ in no way from an ordinary attenuate vibratile flagellum. 



The several new genera and species established by R. S. Bergh are as follows : 



Gymnodinium gracile, Bergh. Body elongate-conical, from two and a half 

 to three and a half times as long as broad, subdivided by the transverse ciliary 

 furrow into a shorter acuminately pointed anterior and a longer obtusely rounded 

 posterior segment ; the longitudinal furrow very wide posteriorly j the external or 

 ectoplasmic layer folded and wrinkled ; no myophan layer ; colour pale pink. 

 Length 1-250". HAB. Salt water: Baltic Sea. 



Gymnodinium spirale, Bergh. Body subfusiform, about three and a half 

 times as long as broad, the anterior abruptly narrowed and curved towards the 

 right, the posterior end forming terminally a short conical sword-like point ; the 

 transverse ciliary furrow taking a very oblique spiral course ; the ectoplasmic surface 

 smooth, inclosing a longitudinally striate myophan layer ; colour grey. Length of 

 body 1-400" to 1-250". HAB. Salt water: Baltic Sea. 



* " Der Organismus der Cilio-flagellaten, eine phylogenetische Studien,'' ' Morphologisches 

 Jahrbuch,' Band vii. Heft. 2, 1881, Ss. 177-288 und Taf. xii.-xvi. 



