176 ON THE SOLITARY CORALS, COLLECTED BY DR A. WILLEY. 



EXPLANATION OF PLATES XIX. AND XX. 



Plate XIX. 

 (The small numerals at the sides of several of the figures refer to the cycles of septa.) 



Fig. 1. Desinophyllum tenuescens, n. sp. 



(a) Profile view of the corallum (x 3^). The stalk is covered with small, low granules, 

 the costae only extending for about L5 mm. below the edge of the theca. 



(6) The calice from above (x 4). Primary, secondary and tertiary cycles of septa are 

 present, the two former nearly meeting in the centre of the oval axial fossa. 



Fig. 2. Rhizotrochus levidensis, n. sp. 



(«) Profile view of the corallum (x 3), showing the large radicle and two small 

 rootlets. The epitheca is concentrically marked below, but covered above by incrusting 

 organisms. 



(b) The calice from above (x 3i). The axial fossa is large and deep but closed in 

 below by the fusion of the primary septa, of which the two, situated at its ends, arise 

 rather deeper and are less projecting. 



Fig. 3. Thecocyathus minor, n. sp. 



(a) Profile view of the corallum (x 4i). The epitheca extends almost to the margin 

 of the calice and is transversely marked. Near the attached base it has been eaten away 

 by boring organisms and the costae are exposed. 



(6) The calice from above (x 7). The primary, secondary and tertiary septa are 

 complete ; the quaternary are generally represented by two septa in each system on opposite 

 sides of one of the tertiaries. The pali of the primary septa are smaller than those of 

 the secondaries, while in front of the tertiaries bilobed pali are found where quaternaries 

 are present. The columella ends above in blunt papillae with difficulty distinguishable from 

 the pali. The quaternary septa are not quite so completely developed as the figure portrays. 



Fig. 4. Paracyathus parvulus, n. sp. 



(a) Profile view of the corallum (x 3). The lower part is incrusted by a nullipore, 

 while a Polyzoon has grown up on one side to within a few mm. of the edge of the 

 calice. 



(6) The calice from above (x 6). Three cycles of septa are complete, and in some 

 of the systems quaternaries are found on opposite sides of one of the tertiaries. 



Fig. 5. Paracyathus Ufuensis, n. sp. 



(a) Profile view of the corallum (x 3). The costae are subequal broad ridges 

 extending to the somewhat enlarged base of attachment which is overgrown by nullipores, 

 worm-tubes, etc. No epitheca can be distinguished. 



(b) The calice from above (x 3). The pali in front of the tertiary septa are often 

 bi- or tri-lobed, and are much larger than those of the primaries and secondaries, which 

 themselves project further into the calice. 



