'7 



Trans. Zool. Soc. Lond. VIII, p. 319, PI. XLIIJ. Figs. 9 — 13 and X, p. 240, PI. XLIX. 

 Figs. 4 — 10) from the Mediterranean, but is not at all compressed and has a copious epitheca. 



Corallum attached, either cylindro-conical or very short, encrusted to within a ven 

 short distance of the calicular margin with a thick dead epitheca through which costae here 

 and there erop out. Above die well-defined limit of the dead epitheca is a vitreous epitheca, 

 which may invade the lip of the calicle, but does not conceal the trenchant finely serrated costae. 



The septa, which are in six systems and four complete cycles, are very regular and 

 are exsert, those of the first two cycles being more exsert than those of the third and fourth. 

 Their edges though thin and trenchant are finely crenulate, and their surfaces are most elegantly 

 ornamenteel with radiating crenulate striae. 



The pali, which are 24 in number, are thick, crenated, subprismatic pillars, placed in 

 two crowns opposite the septa of the first three cycles, and particularly well delimited both 

 from the septa and from the columella. 



The columella, which is not deep-seated. consists of a large number (about 40) of small 

 granular discrete pinnacles. 



The septa of the first two cycles are purple-brown, those of the two inferior cycles are 



white tinged with purple-brown at the edge : the pali and the pinnacles of the columella are 



snow-white. 



Height of corallum 20 millim. 



Diameter of the circular calicle 1 1 „ 



The specimen from Station 96 though much shorter, and of denser and coarser consi- 



stence, is not otherwise distinguishable from the deepwater type. 



IX. Subgenus Tropidocyathus Edw. & H. 



Differs from Trochocyathus only in having the lateral costae expanded to form a pair of 

 wings. Even in some species of Trochocyathus the lateral costae are dentate or even auriculate. 



17. Trochocyathus (Tropidocyathus) Lessoni Mich. Plate II. Fig. 14, \\a. 



Flabellum lessoni Michelin in Guerin's Magasin de Zoölogie, 2 m " section, Mollusques et Zoo- 



phytes 1839 — 1844. Zoophytes pi. 6 (1840). 

 Tropidocyathus lessoni Milne Edwards et Haime, Annales des Sciences Naturelles, ser. 3, 



Zoölogie, IX, 1848, p. 327, and Hist. Nat. des Coralliaires, II, p. 57. 



Stat. 59. io°22'.7S., i23°i6'.5E. 390 m. 1 Ex., dead. 



[Stat. 49'. 8°23'.5S., 1 19 4.6 E. 69 m. 3 Ex.] 



[Stat. 260. 5°36'.5S., I32°55'.2E. 90 m. 2 Ex.] 



[Stat. 289. 9 o'. 3 S., i26°24'.5E. 112 m. 1 Ex.] 



I have no doubt that these all belong to Michelin 's species, though the form of the 

 auricles and of the columella is variable. A corresponding variation is noticeable in the series 

 of Trochocyathus pileus just described. Only one specimen was dredged in deepwater and that 

 was dead. 



SIROGA-EXPEDITIE \\\a. 3 



