34 MISS EUTH M. HAEEISON ON NEW ALCTONAEIA 



a very few isolated ones borne directly on main stem and branches. Polyps not retractile. 

 Spicules of barren stem arranged irregularly, spiudle-shaped, bearing large warty 

 prominences. In the branches the arrangement becomes longitudinal and the spicules 

 themselves are longer and more slender. Partition-walls contain spicules of two kinds : — 

 (a) long spindles like those of the outer wall with warty projections, colourless ; (b) small 

 thorny spicules of a crimson colour. Polyp-spicules : crown consists of about five rows, 

 points have each one large pair arranged en chevron, distal ends beset with small spines 

 directed forwards. Tentacles with single row of thorny transverse spicules. 



Colour. Stem white, with a few scattered crimson spicules. Branches crimson, shading 

 to orange in terminal twigs. Polyps orange, with colourless tentacles. 



The species agrees very closely with Studer's description of Siphonogorgia pendula, 

 which, as has been already shown, should more correctly be called Cluronephthja pendula. 

 It differs from it in the immense size of the spicules of the partition-walls and in details 

 of colour. With regard to the latter, colour is such a very variable feature that it 

 cannot be taken as a character of any specific value ; and as to the latter, although 

 a point by no means unimportant, it is scarcely justifiable to create a new species on 

 a single character when the agreement in other points is so close. These large spicules 

 occur' near the base of the colony, and it is quite possible that Studer took his sample 

 from the upper branches, where they are absent. So that it seems safer to retain it in 

 the species Chironephthya pendula as variation bengalensis. 



Hab. Bay of Bengal. 



Chironephthya siphonogorgica, sp. n. (PI. 3. fig. 9; PI. 5. figs. 43, a & b ; 

 PI. 6. fig. 56.) 



One small complete colony, 1*5 cm. high, dividing at a height of '75 cm. into two 

 branches. A larger colony 55 cm. high, but with basal attachment wanting. Branches 

 few in number, not further subdivided and directed obliquely upwards. Polyps borne 

 directly on main stem and branches, and five occurring on stem below the first branch. 

 A definite calyx surrounds each polyp, into which it is completely retractile, and the 

 calyx is capable of closing over the retracted polyp-head. Spicules of stem and branches 

 disposed longitudinally, somewhat loosely packed together ; long curved spindles thickly 

 beset with small rugged warts. The canal-walls contain somewhat blunter spindles with 

 larger but fewer warts. All these spicules are a uniform bright coral-red. The polyp- 

 sjiicules are small and smooth ; the crown has about five transverse rows and each point 

 six to eight spicules with an ill-defined chevron arrangement. All polyp-spicules are a 

 transparent bright yellow. Tentacles are colourless, contain no spicules, and bear long 

 slender pinnules. 



This species has many points of resemblance to a Siphonogorgia, such as the complete 

 retractility of the polyps and the ill-defined chevron arrangement of the point-spicules, 

 but the structure of the stem and branches leaves no doubt that it should be referred to 

 the genus Chironephthya. 



Sab. Bay of Bengal. 



