ZOOLOaY AND BOTANY, MICROSCOPY, ETC. 63 



two of the dark ring-like patches which are particularly conspicuous 

 along the tentacles of a variety of G. memhranaceus found by Koch at 

 Messina and chosen by him for the study of the openings in question. 

 Water is abundantly discharged through the openings, whose alternate 

 changes of form attest the contractility of their margins. 



Structure of Cla^docoryne.* — Gladocoryne floccosa, discovered at 

 Herm, one of the Channel Islands, by Mr. W. D. Eotch, was referred 

 in Allman's monograph of the Tubularians to a separate family, 

 because of its exceptionally compound tentacles. Nothing was then 

 known of its gonophores. 



A second species of the same genus, C pelagica, from Sargassum 

 in the Gulf Stream, was subsequently distinguished by Allman,| who 

 examined only preserved specimens and conjectured that the gono- 

 phores were phanerocodonic. 



Eotch's species has again been found, near Naples, and Prof. G. 

 du Plessis, working at the zoological station, has redescribed and 

 figured it. He observed many histological details not noticed by his 

 predecessors. 



The Mediterranean specimens were never found on stones, but on 

 Sertularians or sea-weeds. They showed a certain mimetism ; brown 

 or orange hydranths distinguished the stocks which frequented 

 Cystoseira of corresponding tints, while various shades of red marked 

 the individuals attached to diverse Florideae. These colours are due 

 to the presence of oil-globules within the flagelliferous cells of the 

 gastric endoderm. The cells in question, as with some other 

 Coelenterates and Turbellarians, feed amoeba-wise on the particles of 

 the Copepods which the hydranth devours. The tentacles are not so 

 irregularly scattered as would at first appear, but are disposed in 

 approximately decussating circlets of four, somewhat as in Cladonema 

 or Stauridium. 



But the most noteworthy item in this new description refers to the 

 gonophores of Gladocoryne. Sexual specimens, dredged from a depth 

 of 30 metres, were forwarded to Professor du Plessis, after his 

 departure from Naples, by Dr. Lang (librarian to the station). These 

 were secured in June. There is now no doubt that the gonophores 

 are not Medusae, but sporosacs. They are inter- (not intra-) tenta- 

 cular, placed between the verticils so that each occupies the centre of 

 the lozenge constituted by four tentacles (two of which belong to 

 each contiguous verticil). The male capsules, observed at all stages 

 of maturity, were oblongo-ovate, on short stalks, and delicately rose- 

 coloured. Their essential products seem obviously developed from 

 the ectoderm. The ovarian sporosacs, shorter in form and deeper in 

 tint, were more opaque. But two female individuals were seen. In 

 the case of both males and females, sexual are smaller than neutral 

 individuals. As the gonophores ripen, the tentacles of the supj)orting 

 hydranth lose their branches, and, becoming shorter, eventually 

 disappear. In this manner atrophied reproductive hydranths ( = gono- 



* MT. Znol. Stat. Neapel, ii. (1880) pp. 176-96 (1 pi.). 

 t Jouru. Liuu. Sue. (Zool.), xii. p. 255. 



