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



At the most of the localities where Anteclon eschrichti is known to occur it is 

 infested by the parasitic Myzostoma gigas, Liitken. Station 48 also yielded Myzostoma 

 jimbriatum, von Graff. 



■_'. Anteclon antarctica, n. sp. (PI. I. figs. 6, a-cl, 7, a, b; PI. XXV.). 

 Specific formula — A. y . 



Centro-dorsal hemispherical, thickly covered with cirrus-sockets. Eighty or more 

 cirri, reaching 35 mm. in length, and consisting of twenty-five to thirty-five joints, 

 several of which are longer than wide. The later joints project slightly beyond the 

 bases of their successors, and the penultimate has a well-developed terminal claw. 



First radials invisible, except at the angles of the calyx, where they are sometimes 

 separated by the ends of the basal rays ; the second quite short and band-like, very 

 convex in the centre and deeply incised. Axillaries usually rather wider than long, 

 subtriangular, with a backward process of variable size in the middle of the base, some- 

 times so large as to give the plate an unequally rhombic appearance ; first brachial much 

 incised, with a short inner and lono; outer eds;e. 



Ten arms, but slightly tubercular at the base, the joints after the third syzygy being 

 quite short, triangular and slightly overlapping. They become slowly quadrate towards 

 the ends of the arms, but always remain wider than long. Syzygies in the third, eighth, 

 and twelfth brachials, and then usually at intervals of three joints. 



Lower pinnules long and flagellate, with a serrate rlorsal edge, reaching 25 mm., and 

 composed of about sixty short joints, the basal ones rather wide. 



The first two pinnules are nearly equal ; but the third, though of about the same 

 length, consists of fewer and larger joints, some of the lower ones being as long or 

 longer than wide. The following pinnules shorter and more massive,with large lower 

 joints, which are nearly square in outline and overlap considerably. The middle and 

 outer pinnules of more elongated but still overlapping joints, the two lowest broader and 

 more flattened, with their apposed edges incurved. 



Disk and ambulacra naked ; sacculi abundant. 



Colour in spirit, — light brown. 



Disk 17 mm.; spread about 25 cm. 



Locality.— Station 151, February 7, 1874; near Heard Island; lat. 52° 59' 30" S., 

 long. 73° 33' 30" E.; 75 fathoms ; volcanic mud. Several specimens. 



Remarks. — This is no doubt the species to which Sir Wyville Thomson referred 

 when he stated that Anteclon eschrichti had been obtained in the Southern Ocean. 



The two types are unquestionably very closely similar in their general appearance ; , 

 but at the same time they differ considerably in points of detail. The cirri of Anteclon 



