INVERTEBRATA, CRYPTOGAMIA, MICROSCOPY, ETC. 461 



cells, but with no direct connection with the gastrovascular cavity, as 

 two or three small endodermic cells cover them. Further up, 

 towards the base of the cavity of the gonangium, the coenosarc gives 

 origin to lateral diverticula. One cf them presents in its interior a 

 small cavity, the cavity of the cascum of the blaslostyle, bounded by 

 a series of endodermic cells. To the outer surface of this layer is 

 attached a young ovum. The intermediate lamella passes above tins 

 ovum; and further out is the ectodermic lamella. In the upper 

 gonophores the same conditions exist, but the ova become more and 

 more voluminous. When the ovum is mature the tissues surrounding 

 it are in process of atrophy. The endodermic origin of the ova is 

 therefore evident. 



Bringing together these observations, and those of E. van Beneden 

 and Bergh, the author concludes that in the family Campanularidaa, 

 the spermatozoids are developed at the cost of the ectoderm, and the 

 ova at the expense of the endoderm. 



Lafoea parasitica — New Species of Campanularian.* — While 

 working at Scrtularians at the Trieste Zoological Station, Professor 

 Ciamician obtained specimens of an Arjlaoplienia as yet undescribed, 

 upon which large hydranths of a Campanularian seemed to be grow- 

 ing. These turned out to belong to a new species of Lafoea. The 

 hydrorhiza is threadlike and creeping, the hydrothecae are large 

 cylindrical cups without operculum, seated on very short two or three- 

 ringed pedicels, and tlie hydranths are cylindrical with conical 

 hypostome. The species is most nearly allied to L. parvula and 

 L. pygmcea. 



The creeping hydi'orhiza of the parasite follows all the windings 

 of that of the Aglaophenia, and ascends the hydrocauli of the latter, 

 bearing hydranths disposed alternately at jiretty regular intervals. 

 That the ascending processes of the hydrorhiza must not be regarded 

 as hydrocauli is shown by their not terminating in a hydranth at the 

 upper extremity, as is the case in tlie hydrocauli of all Campanularians, 

 All that correspond to hydrocauli arc the short lateral pedicels of the 

 hydranths. 



The parasite does not wind around the Aglaophcnia, but is attached 

 to one side of it. Tlie perisarc of the two hydroids cannot be separated 

 cither by maceration or by mechanical means. 



Attention is drawn to the fact that gonophores have never been 

 observed among the Lafueidic, and suggests that reproduction may take 

 place, as in Sehizocladium ramosmn Alluian, by budding <.>nly ; or, at 

 least, that sexual forms may only occur at rare intervals. The perisarc 

 of the ascending hydrorhiza in L. parnsitlca remains open at the ends, 

 so that a bud from the tonninal co'Uosarc might iiasily bo set free. 



The remarkable dcvelojunent of the hydrautlis and of the ascending 

 hydrorhiza, and the unusual regularity in disjiosition of the hydrantlis, 

 in this as compared with tlic other species of Lnfiwa, which grow ou 

 stones and algie, as well as its restriction to a single species of 

 Aijlaophcnin, are finally pointed out. 



* ' Zfilschr. wiss. Zool.,' xxxiii. (18H0) p. G73. 



