12 IDJIOXEID.J;. 



Prof. Smitt's fcxperience, however, wuiild appear to lead to the 

 belief that it sometimes does so ; and that able observer has thence 

 been induced to place Idmonea in the same family, in fact as a sub- 

 genus of Ttihulipora. At present, from my own observation, 1 am 

 unable to agree with liim o;i this point. 



3. Idmonea milneana, D" Orb. (Plate XI.) 



Zoariura spreading, ramose, dichotomous, each longer branch 

 usually terminating in a pair of short foi-ks ; tubes very slightly 

 exserted, flattened, and even ; aperture wide, margin thick ; four 

 cells in each series. Surface finely dotted, slightly suleate behind ; 

 dorsal surface convex, usually marked with concentric lines of 

 growth. 



Idmonea milneana, UOrhi</ntj, Voy. Amer. Meiid., Poli/piers, p. 20, 

 pi. ix. figs. 17-21 ; Pal. Fkuk;. p. 732; Smitt, Floriclan Bnjozoa, 

 pi. iii. tigs. 14, 19. 



? Idmonea transverea, M.-Edw. I. c. p. 2(3, pi. ix. fig. 3. 



Hah. lies Malouines (D'Orb.); coast of Tierra del Fuego and 

 Patagonia, 30 fathoms ; Chonos archipelago {Darwin). 



M. M.-Edwards's figure of /. transversa appears to represent /. 

 mUneitna. 



4. Idmonea contorta, n..sp. (Plate VIII.) 



Zoarinm irregularly branched or lobate ; branches, or lobes, 

 nearly uniform in size, variously contorted, sometimes inosculating ; 

 cells usually connate and immersed throughout, sometimes much 

 produced and projecting, 5-7 in each series. Surface finely punc- 

 tured ; dorsal surface convex, marked with concentric lines of 

 growth. 



Hah. Algoa Bay, South Africa. 



o. Idmonea notomala, n. sp. (Plate XII. a.) 



Zoarinm dichotomously branched ; branches flattened or concave 

 behind, rounded in front ; cells deeply immersed, 3-5 in each series 

 (usually 4) ; the series on either side are separated by a wide inter- 

 space, in which there are no openings of cells. 



Hab. Easel Amoush, Mediterranean (H.M.S. 'Porcupine'). 



As the specimens upon which I have ventured to found this spe- 

 cies, brought home by the ' Porcupine ' Expedition, consist of only 

 four or five small worn fragments of evidently an old dead growth, 

 the above characters will apply only to the advanced stage of deve- 

 lopment. They are, however, sufficient to distingitish the form to 

 which they belong from any other with which I am acquainted. 

 That it has no relation with /. atlaniica is at once obvious ; nor does 

 it agree with any of the forms described bj' Heller or ileneghini 

 under the names of /. froudoxa, gracilis, scrpula. incDcr/hinii, triforis, 

 iuhvliporn. and ircfqulnris. There only remains, therefore, /. 



