136 ON A NEW MADREI'OKARIAN CORAL. [Feb. 16, 



the Sclerodermic Zoantharia, Ed. and H., or Madreporaria. — 

 Journ. Linn. Soc, Zool. vol. xviii. p. 1. 



4. Fowler, G. H. The Anatomy of the Madreporaria, I. — Quart. 



Journ. Microsc. Science, vol. xxv. p. hi! . 



5. Koch, G. v. Bemerkungen iiber das Skelet der Korallen. — Mor- 



phol. Jahrbuch, vol. v. p. 316. 



6. MosELEY, H. N. On the Colouring Matters of various Animals. 



— Qnart. Journ. Microsc. Science, vol. xvii. p. 1, 1877. 



7. Hertwig, O. und R. Die Actinieu. Jena, 1879. 



8. IIeider, A. V. Die Gattuiig Cladocora, Ehreab. — S. B. Acad. 



Wien, vol. Ixxxiv. p. G34. 



9. Koch, G. v. Ueber die Entwicklung des Kalkskeletes von Aate- 



roides calycularis und dessen morphologischen Bedeutung. — 

 Mitt. Zool. St. Neapel, vol. iii. p. 284. 



EXPLANATION OP THE PLATES. 



Pl.vte XII. 



Fig. 1. Diagram of Sfephanotrochus to show the arrangoiuont of tentaclea, 

 mesenteries, and septa ; on the left-hand side are shown the tentacles, 

 arranged in four cycles, a, h, c, and d; on the right side above are 

 seen the mesenteries, shaded, in pairs of two sizes /' and I", with 

 longitudinal muscles facing one auotiier ; at B is seen the direct ive 

 mesentery, with its longitudinal muscle facing outwards ; the septa in 

 five cycles are numbered from 1 to 5 ; p' and p" denote the pah, C the 

 columella. 



Plate XIII. 



Fig, 2. Oral view of Sfephanofrochm moseleyamis, with the soft parts removed 

 from all except the left upper corner of the coral (nat. size). 



3. Aboral view, the tissues being left in the right upper corner. 



4. Side view of the coral. 



5. View of a secondary and quinary septum, seen from the side : p', palus 



of secondary ; p" , palus of quiuary septum ; /■, coslif, with blunt points. 



6. Section of the end of the knob of a t^ontacle : Ec, ectoderm ; M, meso- 



derm ; En, entoderm; Tli.c, thread-cells; Lm, longitudinal muscle- 

 fibres ; Cm, circular muscle-fibres. 



7. Part of a longitudinal section of a mesentery, showing — En", entoeoelio 



endoderm ; En', ectocalic endoderm ; m', longitudinal muscle-fibres 

 of the entocwlio face ; m', oblique muscles of the ectocoelic face ; 

 M, mesoderm lamella. 



Plate XIV. 



Fig. S. Ectocoelic face of a larger mesentery, showing arrangement of muscle- 

 fibre lines: mf. mesenterial filaments; o, ova. 

 9. Eutocoelic face of the same mesentery, showing the longitudinal muscle- 

 fibre lines. 



10. Longitudinal section of the ventral end of a mesentery: cal, calyco- 



blasts which lay down the columella, 71/, mesoderm ; oi', ova in all 

 stages of development ; En, endoderm ; m.f, mesenterial filaments with 

 pigment-cells, p. 



11. Central end of a mesentery, with calycoblasts scattered all along the 



coralhun-facing side of the mesoderm ; the mesodermal lamella of the 

 mesentery splits to line the columella on each side, and then turns 

 back to line the septum. 



12. Shows two isolated calycoblastic cells. 



13. Drawn from a flat preparation of calycoblastic cells. 



