(1G4 Mr. E. Kirkpatrlck on 



oscular cliannel being pale reddisli. On dissection and 

 magnification, however, a simple canal with deep longitudinal 

 folds is easily made out; below the cortex the passage leads 

 into a main exhalant canal coming from the centre and into 

 large lateral canals (PL XIV. fig. 2). 



As regards the homologies of the poral vestibules and the 

 shallow, crater-like, oscular depressions, these both seem to 

 be ectodermal invaginations, and the vertical intracortical 

 preoscnlar tube to be the terminal exhalant canal (or gastral 

 cavity?). 



Lendenfeld (7, p. 26), who records eight species of Cina- 

 ch/ra, gives as the definition of the genus : — '' Ausstromungs- 

 offnungen klein, zu Gruppen vereint am grunde kahler, 

 schalen-, kelch-, oder sackformiger Einsenkungen der 

 Oberflache.-" Obviously this definition must be emended, 

 since in C. harbata, the type of the genus, the oscules are 

 simple and separate and open each into a single intracortical 

 channel, which latter receives the main exhalant canals. If 

 for " AusstromungsofFnungen^'' the word "Poren" were 

 substituted, the definition might stand. 



On referring to the descriptions and figures of other species 

 of Cinachyra it seems to me possible that misinterpretations 

 concerning the pores and oscules may have been made in 

 some of them also. In Cinachyra Schuhei; Keller, from the 

 Eed Sea, Keller (3, p. 337, pi. xix. figs. 41, 42) figures a 

 sponge with numerous depressions all apparently alike in 

 general character : fig. 42 depicts an enlarged view of a 

 section showing the surface of one of these depressions ; 

 here we see pores with inhalant canals radiating out from 

 them into the body of the sponge ; at the base of the depres- 

 sion are slightly larger orifices opening into wider canals. 

 Keller assumes that the larger orifices are the oscular openings 

 of exhalant canals. The latter, except that they are a little 

 wider, look very like the inhalant ones, and, a loriori^ it seems 

 unlikely that excrementitious orifices should be situated in 

 the floor of a deep pit surrounded by inhalant orifices, natural 

 selection tending to keep the inhalant and exhalant systems 

 each out of the way of the other. A comparison with 

 C harbata would lead one to suggest that the depressions in 

 C. Schidzei are poral vestibules, and that extremely con- 

 tracted oscules situated elsewhere (probably near the summit) 

 have escaped notice. 



Cinachyra eurystoma, Keller (3, p. 338, pi. xix. figs. 46, 

 48), from the Eed Sea, looks like a young immature form; 

 young specimens of C. harbata have several relatively large 



