REPORT ON THE CRINOIDEA. 347 



divisions there are three distichals and three palmars, just as in Actinometra parvicirra ; 

 but sometimes there are only two palmars ; and in one case this arrangement is followed 

 by a post-palmar series of the same character, which does not seem to be due to regenera- 

 tion (PI. LXVII. fig. 1) ; but as it may not occur in other individuals, I have enclosed 

 the sign for it within brackets in the specific formula. 



Apart, however, from the possible presence of the two-jointed post-palmar series, 

 Actinometra littoralis differs from Actinometra parvicirra and Actinometra trichoptera 

 in the more complete reduction of its centro-dorsal. This is not quite lowered to the 

 level of the radial pentagon, from which it is separated by commencing clefts, a condition 

 not reached by any specimen that I have seen which in other respects presents the 

 general characters of Actinometra parvicirra. A minor point of distinction between 

 the two species is afforded by the overlap and the very spiny margins of the lower 

 pinnule-joints in Actinometra littoralis ; while the terminal comb disappears earlier than 

 is usually the case in Actinometra parvicirra, though it is well-developed on the proximal 

 pinnules (PL LXVII. fig. 2). 



9. Actinometra regalis, n. sp. (PI. LXVIIL). 

 Specific formula — a.3. 3. 3.3.—. 



Centro-dorsal a rudely circular disc, much hollowed in the centre, and bearing fifteen 

 to twenty marginal cirri, of fifteen nearly equal segments ; the penultimate without an 

 opposing spine. 



Three radials visible, the second closely united laterally ; axillaries short, widely 

 triangular, and in contact laterally. The rays may divide five times but do not spread 

 much, as the first joints beyond each division are closely united laterally. The rays and 

 their divisions are united by interradial plating to the level of the distichal axillaries or 

 slightly beyond it. Each division of three joints, the third of which is axillary with a 



syzygy- 



Arms very numerous, thirteen to twenty-four on a ray. They have moderately long, 

 triangular, and much-overlapping joints, which soon become quadrate and are nearly 

 square at the ends ; the anterior arms have one hundred and sixty, and the posterior 

 only sixty or seventy joints. Syzygies in the third and the tenth or twelfth brachials, 

 and then at intervals of two to six, usually three or four joints. 



The distichal and palmar pinnules are of about equal size, reaching 15 mm.; the 

 length diminishes to that on the second brachial, which is considerably shorter, and 

 those of the fourth and fifth brachials are much more so, after which the length increases 

 again. Later pinnules of the anterior arms not specially long ; terminal comb to the 

 tenth brachial. 



