NOTES ON SOME SPECIES OF RETEPORA AND ADEONELLA 



outside of this by a series of marginal pores which grow smaller dis- 

 tally ; whereas, the older zooecia (c) are irregularly hexagonal and 

 somewhat depressed in the frontal parts, the marginal pores becoming 

 very small or nearly filled in by growth of the shell. Blind zooecia, 

 frequently occur in the proximal parts of colony, and in those zooecia 

 the median pore has entirely disappeared, there remaining only a few 

 marginal pores. Frontal avicularia (d) with triangular mandible which 

 is simply pointed at end without curving ; they are about one half as 

 large as the vicarious avicularia. The younger zooecia (b) have each 



Fig. 6. 



Fig. 6. Adeonella japonica Ortmann. 



a. View of a young zooecium with zooid within, xca. 70. 



c.s. compensation sac. me.p. median pore. 



tn.p. marginal pore. op. operculum. 



oc m. occlusor muscle. p.m. partietal muscle. 



p.v.m. parieto-vaginal muscle, r.m. retractor muscle. 



b. Two young zooecia. x 30. 



c. An older zooecium. X30. 



d. Mandible of frontal avicularium. x 150. 



e. Mandible of vicarious avicularium. x 150. 



a single frontal avicularium, while the older zooecia (V) have two of 

 same, the one placed below zooecial aperture being always larger than 

 the other. The median pore is circular in young zooecia, while in 



