80 THE VOYAGE OF H.M.S. CHALLENGER. 



Habitat. — Station 232, Hyalonema-ground, south of Japan ; depth, 345 fathoms ; 

 bottom, green mud. 



[Formosa (Gray) ; Japan (Dr. Hilgendorf, Dr. Doderlein) ; Mauritius (Bern 

 Museum).] 



[6. Caligorgia comi^ressa (Verrill). 



Prymnoa veriiciUaris, Ehrbg., CoralL d. roth. Meeres, p. 133. 



Primiioa compressa, Verrill, Proc. Essex. Inst., 1865, p. 189. 



Fanellia compressa, Gray, Cat. Lithophytes Brit. Mus., 1870, p. 46. 



Calligorgia verticiUata, Gray, op. cit, p. 35. 



Monilia anmilata, Valenc, Paris Museum, Jardin des Plantes. 



Calligorgia compressa, Studer, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, 1878, p. 647. 



Habitat. — Aleutian Islands (Verrill) ; North Pacific Ocean (Adalbert von Chamisso, 

 Berlin Museum). 



This species is distinguished, independently of the very strongly compressed axis, by 

 the great number of polyps, ten to twelve of which form a whorl, and the form of the 

 calyx scales. These latter are very broad, measuring 0'41 by 0"2 ; 0'4 by 0"3 mm., and 

 are covered with prominences, which, however, form sharp spines rather than coarse, 

 thorny protul^erances. The upper edge of the scale is more obtusely but more richly 

 toothed than in Caligorgia Jlabellwn. The opercular scales likewise exhibit thorny 

 protuberances up to the very edges. The spicules of Monilia annulata, Val., in the col- 

 lection of the Museum of Paris, agree completely with those of the typical specimens.] 



Genus 8. Primnoella, Gray. 

 Frimnoella, Gray, Proc. Zool. Sec. Lend., 1857, p. 286. 



The genus Primnoella was instituted in the year 1857 by Gray for a Primnoid 

 which he had described in the year 1849 under the name of Primnoa australasiae. Gray's 

 diagnosis runs : — " Coral simple, elongate, cylindrical. Axis continued, stony. Bark 

 granular, smooth. Polypiferous cells numerous, close pressed, subcylindrical, regular, 

 small, placed in close regular circles, each containing many cells round the stem ; each 

 cell covered with two series of small imbricate scales." 



The tj^e species is Primnoa australasiae, Gray.^ Gray also refers Primnoa vetusta, 

 KoUiker, to this species.^ Kolliker figures sections of the axes of a Gorgonellacean, 

 which, in the description of pi. xiv., is described as Juncella vetusta under fig. 12, and 

 as Primnoa vetusta under fig. 19. The specimen came from Michelotti and was described 

 by him as Leiopathes vetusta in manuscript. Since Kolliker in the text of his book only 



I Cat. Lithophytes Brit. Mus., 1870, p. 50. 

 * Icon. Histiol., pi. xiv. figs. 9, 12. 



