REPORT ON THE ALC YON ARIA. 177 



The colony is branched in the one plane, fan-shaped. The largest specimen measures 

 about 150 mm. in height by about 100 mm. across the widest part. An anastomosis 

 between both nodes and internodes is frequent and occurs from the basal portion of the 

 (;olony to the very ends of the branches. In the basal portion of the main axis the 

 nodes and internodes become confluent with, those of the parallel branches, forming a 

 massive stump-like base. In the upper meshes the internodes vary from 4 to 8 mm. in 

 length, with an average diameter of 1 mm. The nodes are well marked, slightly more 

 jirominent on the back of the colony, 1'5 mm. in diameter. 



The polyps are arranged on the sides of the branches, but while sometimes assuming 

 a quite bilateral arrangement, at other times they are found in clusters, extending over 

 the front of the branches, and on the tips of the branches they are even found all round. 

 They are retractile, within distinct verrucse, which are from 0'5 to 1 mm. in diameter; 

 sometimes the verrucse project but little beyond the surface of the coenenchyma. In one 

 colony besides the ordinary sized polj^js, others are to be found the verrucse of which 

 measure 1'5 mm. in diameter and 1'25 mm. in height ; those examined were found to be 

 full of ova. The coenenchyma is moderately thick and rough with spicules. 



The colour of the colony varies ; one being of a light yellow colour with the polyps 

 of a vermilion red ; in another the yeUow is of a brighter hue and the verrucas are pink ; 

 and in a third, of which there are but a few fragments, the colour is of a pure white with 

 pink verrucse. 



The spicules measure : — the club-like spindles 0'18-0"04 ; O'lG-0'06 mm. The bent 

 warty spindles 0-2-0-08; 0-2-0-06; O'lG-Q-OS mm. The Stachelkeule measure 0-1-0-04; 

 0'l-0"06 ; 0"14-0'04 mm. The one-sided spiny spindles 0'06-0"06 mm. Four-rayed 

 forms 0-12-0-06 mm. The curved spiny spindles on the pol}q3S 0-2-0 "02 ; 0-16-0-02 ; 

 0'14-004 mm. The irregularly branched spindles 0'14-0"1 mm. in broadest, and 0"02 mm. 

 in narrowest diameter; the double crosses 0'06-0'04 mm. 



Habitat. — Reefs, Samboangan ; February 1, 1875. 



Melitodes sinuata, n. sp. (PI. XL. fig. 9). 



A small but possibly nearly complete colony of this species is in the collection ; it 

 wants the basal attachment and is also somewhat frayed away towards the terminal 

 branches. It is fan-shaped and measures 90 mm. in height and about the same in 

 greatest width. The branches freely anastomose, giving rise to a complicated series of 

 meshes, into which very short lateral branches protrude. The nodes ^re large, measuring 

 3 '5 by 3 mm. in the basal portion of the colony, and 2 by 2 mm. in the terminal twigs. 

 The internodes vary greatly in length, being from 4 to 10 mm. towards the cu-cum- 

 ference, and not more than 2 mm. at its basal portion. The basal internodes measure 2'5 

 mm. in diameter, the terminal ones 1 mm. When denuded of coenenchyma the basal 



(ZUOL. CHALL. EXP. — PART LXIV. — 1888.) Sss 23 



