NOTES ON SOME SPECIES OF RETEPORA AND ADLONEL'.A 



627 



surmounted each with a short oral spine {h). Ventral avicularia are 

 distinguishable into three forms, «, b and c, each with two retractor 



Fig. S. 



Fig. 5. Retepora crennlata, n. sp. 



a. Two zooecia with ovicells. x 30. 



b. A few zooecia with three kinds of frontal avicularia. x 30. 



c. The operculum and two pear-shaped oral glands hanging down from 

 the distal margin of tentacular sheath, x 100. 



The shield-like mandible (a) of frontal avicularium with two retractor 

 muscles and an avicularian gland, x 2oq, 



e. The semicircular mandible (/') of front il avicularium. X300. 



f. The triangular mandible (r) of frontal avicularium. x 200. 



g. The elongate shield-like mandible of vicarious avicularium. x200. 



h. Young zooecia ; one of them with oral spines on the toathed apertural 

 margin. X30. 



muscles and a single avicularian gland. Form a (d) is of an 

 oblong shape, with variously directed, elongate shield-like mandible 

 which is pointed and slightly curved at apex; it is situated at varying 

 positions in the middle or rather posterior parts of ventral zooeciaL 

 surface. Form b (e) is of an oval shape, found in the same 



