74 Mr. II. J. Carter o/i the Sponrjes 



this is the h'vtn;/ s[)eeies tliat T have had uiuh'r observation), 

 that Jjaeaze-Duthior.s's figures (viz. 1-8, wliieli are the ])riii- 

 cipal ilUi-strations to Sehinidt's de.seription) ^vcrc made during 

 lite, and that Sehniidt's OAvn (viz. 9-13 inclusive) have the 

 contraeted forms ])re.sented to Schmidt in tlic preserved speci- 

 men. 



Although Selimidt's section of the two pa])illa^ (fig. 12), re- 

 presenting tlie sarcodal columns in coniu^xion respectively with 

 large canals helow them, while the latter, again, are stated to 

 o|)en on the surface by several little orifices between the co- 

 lumns (that is to say, sieve-like), is exactly like the structure 

 of the pa])illiform inhalant area of GrayiUa (see my figures, 

 /. c.),yet in fig. 11 Schmidt re})resents an osculum, or large 

 excretory orifice, in the centre of the marginated disk of a 

 papilla, in addition to the sieve-like group of little pores close 

 to the margin. If Schmidt be right in considering this an 

 osculum and the group of smaller apertures " inhalant pores," 

 then we must infer that the osculum is in connexion with its 

 own excretory canal, and that the pores have their own inha- 

 lant canals or canal beside it, in which case this is an instance 

 of the combination in one ])apilla of both organs, viz. the ex- 

 current and incurrent system of canals respectively — a ])Ossible 

 combination which I do not deny, but of Avhich I have seen 

 no exam])le either in Grayella or Cliona. 



I say " if right," because Schmidt's observations having 

 been made on a preserved specimen, his distinction of excur- 

 rent and incurrent apertures must be made from resemblances, 

 as, I think, is stated in liis description. 



Now, if Lacaze-Duthiers's fig. 8, representing a mammilli- 

 form eminence terminated by a single large orifice, be viewed 

 as an excurrent organ, and the fringed papilla? respectively 

 with their sieve-like orifices as iidialant area;, then the analogy 

 between Grayella and Osc ^'na becomes very strong. But in 

 Schmidt's description, as L , )re stated, they are all alike re- 

 garded as excretory ; there is no part illustrative of the great 

 inhalant system but the little insignificant group of orifices 

 placed on one side of the disk of a papilla otherwise devoted 

 to the excretoiy system, as above mentioned. 



My impression of such orifices is that, for the most part, 

 excretory openings are large, single, and simj)le, and that it 

 is the oral ones which are tentaculated, fringed, or otherwise 

 ornamented with useful appendages. In Actinia and Hydra, 

 where there is but one orifice for both purposes, it is orna- 

 mented ; but certainly in the Polyzoa and Ascidia^, where 

 there are two, it is the oral, and not the anal, orifice which is 

 thus complicated. Hence, from analogy, I should be inclined 



