OJ 



Stat. 17. 7°28'.5S., ii5°28' E. 1060 m. i Ex. 

 Stat. 18. 7°28'.2S., ii5°24'.6E. ioi8 m. 7 Ex. 

 Stat. 212. 5°54'.5S., I20°I9'.2E. 462 m. i Ex. 



In none of these specimens are the costc-e so prominent as they are in specimens from 

 Indian Seas. 



The specimen from Station 212 is singular in l>aving the coraHum elongate and com- 

 pressed, with the lateral costc-e sharp and almost cristiform, and the septa increased in number; 

 it, however, has all the look F. japoniatm from which I am not inclined to separate it. 



Distribution. Off Japan, Java Sea, Bay of Bengal and Arabian Sea. 



XIX. Placotrochus Edw. & H., Uuncan. 



47. Placotrochus Candeamis Edw. & H. 



Placotroclius Candcaniis Milne Edwards et Haime. Ann. Sci. Nat. Zool. 3 ser. IX, 1848, 

 p. 283, and Hist. Nat. Corall. II, 99. 



Stat. 12. 7°i5'S., 1 1 5° 1 5'. 6 E. 289 ni. i Ex. 



Distribution. China Sea, Java Sea. 



XX. Placotrochides n. gen. 



Two small dead and somewhat broken coralla of the ".Siboea" collection mig-ht be 

 referred to Placotrochus E. & H., but for the presence of a large fascicular columella almost 

 as abundant as that of CaryopJiyllia. From Platytrochus E. & H. they are separated by the 

 absence of the characteristic lateral costee, and by a certain, apparentlj- normal, irregularit)- 

 of growth. 



Corallum simple, compressed, free (or attached ?), indistinctly costate. A pellicular epitheca 

 may be present. Columella essential, elongate, and fascicular. Septa little exsert. No pali. 



48. Placotrochides dcntiforinis n. sp. Plate IV. Fig. 31, -^la. 



Stat. 59. io°22'.7S., 123° i6'.5 E. 390 m. i Ex. dead. 



Corallum free, simple, compressed, acutel)- wedge-shaped, fairly elongate, curved in the 

 plane of the major axis apparently in consequence of increased growth at one end. 



The costae, which correspond in number with the septa, are almost worn away, but 

 appear to have been low, broad, and equal — except that one of the lateral costae seems to 

 have been more prominent than any of the others. 



The calicular orifice is ovate, not regularly elliptical; the axial diameters are as 3:2, 

 and the major axis is on a slightly lower plane than the minor. 



The septa, which are coarse, are in six systems and three cycles with a fourth cycle in 

 a tew of the half-systems. Those of the first two cycles are the largest and reach the columella, 



SIDOGA-EXPEDITIE XVI <r. 5 



