182 THE VOYAGE OF H.M.S. CHALLENGER. 



First radials almost entirely concealed ; the second oblong, and not united laterally ; 

 axillaries acutely triangular. There is a variable amount of calcareous plating on the 

 perisorne between the rays. Ten arms ; the first two brachials tolerably similar in shape, 

 oblong or subtriangular, the second being rather the longer. A few joints after the 

 second syzygy may be triangular, but they soon become quadrate, with the sutures but 

 little inclined, so as to be somewhat squarish in outline, becoming elongated towards the 

 ends. The lower and middle joints may overlap more or less, but the distal parts of the 

 arms are almost smooth. Syzygies in the third, eighth, and twelfth brachials, and then 

 at intervals of one to six joints. 



The second brachial bears a tapering pinnule of some twenty-five or thirty elongated 

 and overlapping joints, and reaches over 10 mm. in length ; that of the third brachial is 

 about half its size, with twelve or fifteen joints. The next pair are of about the same 

 length, and the following pinnules gradually increase, becoming very long and slender 

 towards the arm-ends. 



There are a few scattered granules on the ventral surface of the disk, especially in 

 the anal interradius. Sacculi very abundant on the pinnule-ambulacra. 



Colour in spirit, — yellowish-brown or brownish-white. 



Disk about 7 mm.; spread 8 or 9 cm. 



Locality. — Bahia, 20 fathoms. One specimen. Also Rio Janeiro (Bohlsche), and 

 the Abrolhos (Verrill) ? 



Remarks. — By the kindness of Dr. Otto Hamann of Gottingen I have been enabled to 

 examine and figure the original specimen of this type, which was described by Bohlsche 

 from Rio Janeiro (PL XXXVII. fig. 2). There is a very considerable difference between 

 it and that obtained by the Challenger at Bahia (PI. XXXVII. fig. 1), but their general 

 resemblance is so close that there can be no question of their belonging to the same 

 specific type. The cirri are very uniform in appearance, but the radial axillary has a 

 much greater length in Bohlsche's specimen than in the Challenger one; while the anambu- 

 lacral plating on the perisorne between the rays is reduced in the former to a very definite 

 nodule which intervenes between every two second radials, very much as was figured by 

 Miller 1 in his Comatula Jimbriata ( = Antedon rosacea). In fact it seems to rest directly 

 upon the upper angles of the first radials (PI. XXXVII. fig. 2), and it may possibly 

 represent a true calyx-interradial rather than anambulacral plates, which was shown by 

 Dr. Carpenter 2 to be the case with Miller's type. The lower and middle arm-joints of 

 Bohlsche's example overlap but little, and the basal ones after the eighth are distinctly 

 triangular in outline, but in the Challenger specimen they are quadrate from the first and 

 overlap considerably, so that the dorsal line of the arm is markedly serrate (PI. XXXVII. 

 fig. 3). In this form too the syzygial interval is often five or six joints, while it is 



1 Op. cit, Frontispiece, tig. 2. - Phil. Trans., 1866, p. 716, pi. xxxiii. fig. 7, a, b. 



