OE LITTLE-KXOWX COMATUL^!;. 513 



About the middle of the ann they become more equal-sided, and 

 are nearly oblong iu the terminal portions. 



First syzygium on the third brachial, and the next from 11-15 ; then 

 an interval of 6-12, usually 8 or 9, joints between successive syzygia. 



First pinnule on the second distichal, quite short ; but the next 

 three on the outside of the arm (on 2nd palm., 2nd & 4th br.) are 

 rather longer. They all have somewhat the appearance of being in 

 two parts, as if they had been broken and regenerated. The lower 

 half consists of wide and thick joints with dorsal keels ; while the 

 upperhalf is composed of quitesmall joints, and grows, as it were, out 

 of the middle of the wide loAver portion. This is least marked iu 

 the pinnule on the fourth brachial, which is nearly twice as long- 

 as that on the second joint, stouter, and more uniformly tapering. 

 The next (on 6th br.) is still longer, reaching 25 mm., and consists 

 of about 50 broad joints, the lower ones of which are keeled; the 

 following one (on 8th br.) is nearly as long, but less stout. On the 

 inner side of the arm the seventh joint bears a large pinnule like 

 the preceding one. That on the fifth joint is much smaller, and 

 that on the ninth variable, sometimes small and sometimes nearly 

 as large as its fellow of the fourth pair. In some arms the fourth 

 or eighth joint may bear the largest pinnule. Beyond the fourth 

 pair the length decreases, rapidly at first, but afterwards more 

 gradually till about the 20th joint, beyond which the pinnules are 

 tolerably uniform in size, decreasing again towards the arm-ends. 

 The carination of the basal joints of the lower pinnules dies away 

 gradually, and is lost after the tenth pair. 



Disk naked and much incised, 15 mm. in diameter. Colour 

 deep purple, almost black. Sacculi closely set along the pinnule- 

 ambulacra. 



Spread nearly 25 centim. 



One specimen from Hongkong. 



BemarJcs. — This is one of the very few species of Antedon which 

 have three joints in the secondary as well as in the primary arms. 

 I know of but seven species belonging to this section of the genus, 

 in three of which the rays divide a fourth or even a fifth time. 

 Apart from this character, they are altogether different from the 

 epecies under consideration, which comes nearest to Antedon 

 Philiberti, MiilL sp., from Java. It differs, however, in the 

 peculiar shape of the lowest pinnulchi, and in the undeveloped 

 condition of the terminal cirrus-joiuti':', none of which, even the 

 penultimate, bear dorsal spines. 



38* 



