\--. I. Stat. 257. In Du-roa Strait, Kei Islands, o — 52 Metres; coral. 



20S. F. Stat. 282. Anchorage between Nusa Besi and the N. E. point of Timor, 27 — 54 Metres; 



sand, coral and Lithothamnion. 

 223. A. Stat. 305. Mid-channel in Solor Strait, off Kampong Menanga, 1 13 Metres; stony bottom. 

 412. A. Stat. 310. 8° 30' S., M9°7".5E., 73 Metres; sand with a few pieces of dead coral. 



Also, in the Collection of the University Museum of Zoology, Cambridge : — 



Torres Straks, 194. A. C. Haddon Coll., Reg. Feb. 24, 1898. 

 Singapore, 5 — 10 fathoms, F. P. Bedford Coll., Reg. Nov. 11, 1899. 



Ceylon, L. R. THORNELY Coll., Reg. Apr. 25, 1906 (determined by Miss ThüRNELY as 

 Idmonea milneana). 



Lifu, Loyalty Islands, A. WlLLEV Coll., Reg. Mar. 1, 1898 (determined by Miss PHILIPPS as 



I. interjuncta). 

 Port Denison, Queensland, Miss E. C. JELLV, Reg. May 24, 1895. 

 Japan, Uraga Channel, off Tokyo, 30 fathoms, A. OWSTON Coll., 49. K, 7. S + 15. B, Reg. 



June 23, 1902. 



Zoarium large, reaching a diameter of at least 45 mm. (412. A.) ; its branches commonly 

 in one layer, often nearly in one plane, but sometimes variously curved. In the majority of 

 cases the zoarium is more or less reticulate, owing to the existence of cross-connexions between 

 the branches. Stout rooting processes, consisting of a bundie of parallel kenozooecia *), are 

 usually given off, here and there, from the middle of the basal surface of the branches. Basal 

 surface not limited by sharp edges, flat or gently convex, the longitudinal septal lines distinct; 

 usually without transverse lines of growth. Frontal surface of branch nearly fiat, without a 

 median ridge. Series consisting of 2 — 3 zooecia, rarely 4, the outer zooecia the longest. Some 

 of the median peristomes are commonly somewhat separated from their neighbours of the same 

 series, and appear more or less isolated in the middle of the branch. Ovicell variable, either 

 simple or bifurcating with the branch, the frontal surface only slightly convex. Ooeciostome 

 typically single, with a much infiated basal portion, of an urndike shape. Accessory ooeciostomes 

 are rarely present, and may be of simpler structure than the principal ooeciostome. 



This species is represented by a number of specimens in the 'Siboga' dredgings. As 

 in the case of so many other Cyclostomes, there is a considerable amount of variation in 

 size, arrangement of zooecia and other characters. These variations may depend on the general 

 vigour of growth. Thus the ovicells shown in hg. 4 are developed in the course of branches 

 of a large reticulate colony; while in fig. 1 the ovicell is formed in a very small colony whose 

 zooecia had not attained the typical adult arrangement at the time when the ovicell commenced 

 to develop. 



In well branched colonies the zooecia have the disposition shown in those parts of 

 fig. 4 where an ovicell is not present. The rather flat frontal surface of the branch is associated 

 with the fact that the median zooecia are not specially raised. The alternating series consist 

 most commonly of two or three zooecia, or alternately of two and three; the outer zooecia 

 being the longest and often having their peristomes much prolonged. The median peristomes 

 are frequent!)- separated from their next neighbours by a distinct interval, as shown in the 



1) This term was introduced by Ltsvinsen (1902, "Studies on Bryozoa", Vidensk. Mcdd. Naturb. Foren. Kjobenhavn, p. 3) for 

 zooecia "which lack both a polypidu and an orifice". 



130 



