19 



Corallum white : the soft parts, in spirit, are also whitish. 



In the type specimen the greatest height of the corallum is 28 millim.. the major dia- 

 meter of the calicle 19.5 millim., and the minor diameter of the calicle 15 millim. 



XI. Deltocyathus Edw. & IL, Duncan. 

 Four species of this genus are represented in the collection, including a magnificent 

 specimen of D. magnificus. 



Synopsis of the Siboga species of Deltocyathus. 



I. Septa in six systems and four complete cycles : 



1. Corallum discoid or saucer-shaped : conspicuous pali before the septa 



of the first three cycles \. D. italicus. 



2. Corallum onion-shaped, the pali before the secondary septa alone are 



distinct 2. D. lens. 



II. Septa in six systems and five complete cycles: 



1. Corallum discoid, dense septa echinulate 3. D. magnificus. 



2. Corallum saucer-shaped, thin and fragile : septa non-echinulate. ... 4. D. fragihs. 



20. DcltoeyalJius italicus (Michelotti) Edw. & H. 



Deltocyathus italicus Milne Edwards et Haime. Annales des Sciences Naturelles, 3 ser., Zool. 

 IX, 1848, p. 326, pi. X. fig. 11, and Hist. Nat. des Coralliaires II, 56: Pourtalès, Bulletin 

 of the Museum of Comp. Zool. Vol. VI, 1879—80, p. 101, pi. I, figs. 1- 8. Moseley, 

 Challenger Deep-Sea Madreporaria, p. 145. Jourdan, Hirondelle Zoanthaires (Monaco, 1895) 

 p. 16, pi. I. figs. \\a — d. 



Deltocyathus agassizii Pourtalès, Buil. Mus. Comp. Zool. Vol. I, 1863 — 69, p. 113, and 

 Vol. V, 1878 — 79, p. 200 ; and Illustrated Catalogue of the Museum of Comp. Zool. N° IV, 

 1871, p. 15, pi. II. figs. 1—5 and pi. V. figs. 9— 10, and N° VIII, 1874, p. 35, pi. VI. 

 fig. 11. Lindström, K. Svenska Vetenskaps-Akad. Handl. Bd. XIV, 1S76, N° 6, p. 10, 

 pi. I & II, fig. 13 — 20. 



Stat. 45. 7 24' S., ii8°I5'.2E. 794 m. 1 Ex. 



Stat. 95. 5°43'.5X., ii9°4o' E. 522 m. 1 Ex. 



Stat. 100. 6° 11'. N., i2o°37'.5E. 450 m. 2 Ex. 



Stat. 251. 5°28'.4S., 132 o'. 2 E. 204 m. 1 Ex. 



I do not from the description and figures appreciate the distinction between this species 

 and D. ornatus Gardiner. (On the Solitary Corals collected by Dr. A. Willey : Willey's 

 Zoological Results part. II, p. 163). 



Distribution. Atlantic (West Indies and neighbouring coast of America, Bermuda, Azores 

 and E. Atlantic), East Indian Archipelago (" Challenger 1 ' and "Siboga"), South Pacific. Miocene 

 of Northern Italy. 



21. Dcltocyatlius lens n. sp. Plate II. Fig. 16, \ba. 



Stat. 59. io°22'.7S., I23°i6'.5E. 390 m. 2 Ex. 



Stat. 95. 5°43'-5 N., U9°4o' E. 522 m. 3 Ex., dead. 



Stat. 256. 5°26'.6S., i32°32'.5E. 397 m. 1 Ex. 



Stat. 275. 4°52'.5S., i2S°37' E. 4914 m. 3 Ex. 



Corallum onion-shaped or lentiform. Costa? all ecpial and all distinct from calicle to 

 base, sharply salient and elegantly serrulate. 



