NOTES ON SOME SPECIES OF RETEPORA AND AÜEONELLA 



617 



culum (c) semicircular, thin, transparent, and with narrow marginal 

 sclerite which bears on each side of its proximal end a small vertical 



flange for the attachment of the 



Fig. 1. 



Fig. I. 



tendon of the retractor muscle. 

 There occur two well developed 

 oral glands, opening on the distal 

 margin of tentacular sheath. 

 Avicularia (e) of a moderate size, 

 not present on all and every 

 zooecium, usually placed below 

 zooccial aperture ; provided with 

 an elongate subrectangular man- 

 dible, pointed and bifid at end 

 and with a small circular lucida 

 in the cen're, directed upwards or 

 obliquely so. Avicularian gland 

 consisting of two dissimilarly 

 shaped vesicles, one elongate and 

 gently constricted in the middle 



Retepora misaldi'iisis, n. sp. 



a. A few zooecia, two of which are prov 

 ded with zooecia, X40. 



b. Young zooecia, with longitudinal folds and the other subglobular and 



on frontal wall. X40. , . , i-™ , - 



^ , somewhat larger. Ihe ducts of 



c. Operculum, x 150. 



d. Mandible of dorsal avicularium x 150. both the vesicles unite after a 



e. Mandible of frontal avicularium with 1 t ■ . , • , 



.._ _ , short course into one which opens 



bifid end. x 150. 



externally at a point near the lower 

 margin of the mandible. Ooecia (a) ovoid, broadly rounded above, 

 smooth on surface, the wall with a narrow oblong fissure in the centre, 

 the lower margin prolonged below into a kind of lamina, extending 

 some way into the zooecial aperture, provided with two sinuses at the 

 inferior margin. Dorsal surface nodulous, divided by vibices into 

 numerous, irregularly shaped areas, some of which bear a raised avicu- 

 larium [d) with triangular hooked mandible of nearly the same size as 

 that of ventral avicularium. 



