REPORT ON THE ANTIPATHARIA. 137 



Tybpathes? flabdlum (Pallas), non Esp. (PI. XL fig. 18). 



Antipathes flabellum, Pallas, Elencli. Zooph., p. 211 ; Lamarck, Hist. nat. anim. sans vert, t. ii. 



p. 309 ; Lamouroux, Polyp, flex., p. 382 ; Dana, Zooph., p. 579. 

 Rhipid ipathes flabell urn, Milne-Edwards, Coralliaires, t. i. p. 321. 



"A. explanata ramosissima subdivisa, ramulis bifariam ramosis, reticulatim cohaa- 

 rentibus. Lignum stirpis fragilissimum, atrum, tenerrima seabritie hispidum. 

 Calyces a latero convexo flabelli, per ramos sparsi, erebri, grano papaveris vix majores, 

 breviculi, subturbinati, extus scabri " (Pallas, op. cit.). 



In its flattened and trellis-like surface this species has much the habit of 

 Rhipidogorgia flabellum, indeed the form described and figured by Esper may have 

 belonged to this or some allied species, as the axis was smooth and devoid of 

 spines. 



A specimen in the British Museum from Madagascar, which appears to be referable 

 to this species, has a form that is perhaps due to some injury received during growth. 

 The corallum is flattened, but in the middle it becomes folded, so that a flattened plate- 

 like portion grows out at right angles to the general plane of growth and parallel with 

 the axis of the stem. The lower branches come off irregularly, and are fused together by 

 bridges of sclerenchyma which cross obliquely from one to another. In this portion of 

 the colony the sclerenchyma is black and polished, but bears a number of small slender 

 spines only seen by the aid of a lens. In the upper part of the corallum the long- 

 slender branches run almost vertically and are closely set (4 to 10 mm. apart). These 

 are reddish brown in colour and more densely spinose. They bear pinnules given off 

 subalternately from the antero-lateral margins, which are bent upwards and usually fuse 

 with those from an adjoining branch. The pinnules are 3 to 6 mm. long and generally 

 simple, though some of the larger ones bear secondary pinnules springing from the 

 antero-lateral margin and usually free. With these exceptions the whole of the sub- 

 divisions from base to apex are fused into a close reticulum, consisting of long slender 

 subvertical branches and close-set antero-lateral pinnules, so that the surface of the 

 corallum following the pinnules has a zigzag outline. The spines are moderately long, 

 and arranged in subregular dextrorse spirals and also in longitudinal rows. Five rows 

 may be counted from one aspect of a slender branchlet, the members of a row being 

 from one and a half to two lengths apart. The spines are about twice as long as broad 

 at the base, and slowly taper to a moderately sharp point. Most of the spines form 

 a right angle with the axis, but those in certain rows are hooked upwards (PI. XL 

 fig. 18). " 



Habitat. — Indian Ocean (Pallas) ; off Madagascar (Brit. Mus.). 



(ZOOL. CHALL. EXP. — PART LXXX. — 1889.) LIU 18 



