24 PROCEEDINGS OF THE NATIONAL MUSEUM. vol: 43. 



ANTHOMASTUS JAPONICUS, new species. 

 Plate 3, figs. 2, 2a; plate 18, fig. 4. 



Capitulum round, 4.1 cm. in diameter. Total height of colony 7 

 cm., the sterile stem being about 6 cm. in height. The capitulum 

 has its outer edge folded downward so that its edge is 2.2 cm. below 

 its central and highest point. The whole colony is in the shape of a 

 typical toadstool. The stem of this specimen differs from the others, 

 and all other species of the genus thus far described, in having a sharp 

 constriction about 2 cm. from its distal end, below which the stem is 

 produced into a tongue-shaped termination, rounded and even at the 

 end, like many pennatulids. The other specimens end in ragged 

 lobular edges, where the stem has been torn from its support, the one 

 described being the only one that is certainly complete. 



The stem measures 15 mm. in greatest diameter. The polyps are 

 about 45 in number, of which about 30 are situated on the edge of the 

 capitulum. The upper surface is much less thickly emplanted. 

 Smaller polyps appear irregularly among the larger ones,, the latter 

 measuring 12 mm. to base of tentacles, the tentacles themselves 

 reaching 7 mm. in length. The polyp bodies increase in diameter 

 from below upwards, being m some cases 5 mm. in diameter just below 

 the tentacular bases. The body cavities extend directly to join the 

 stem cavity. 



Siphonozooids are densely crowded over the entire upper surface of 



the capitulum between the polyps, giving it a granular appearance. 



Under a low power of the microscope they appear as closely packed, 



.rounded, or cone-shaped verrucas with a pit in the center. Upon 



dissection these siphonozooids are seen to contain ova. 



Spicules : These are almost all needle-like or bar-like forms, nearly 

 smooth, or at least not with pronounced verrucas, as described in other 

 species of the genus. In the polyps there are a number of minute, 

 smooth, barlike spicules, also minute crosses, stars, and double stars. 

 All spicules smaller than usual in the genus. 



Color: The colony is dark red, the polyps somewhat darker. The 

 stem is red above, fading to a grayish-red below. Two specimens 

 from station 5050 were much more brilliant in color than the type, the 

 capitulum and polyps being bright scarlet. 



Localities. — Station 4976; Shio Misaki Light, N. 59° E., 6.4 miles; 

 545-544 fathoms. Station 5043; 42° 10' 20" N., 142° 15' 20" E.; 

 330-309 fathoms (type). Station 5050; Kinka San Light, N. 78° W., 

 25.7 miles; 266 fathoms. 



Type-specimen.— C Sit. No. 30038, U.S.N.M. 



A specimen from station 4976 has a triangular capitulum with 

 large polyps at the corners and a greater diameter of 3.2 cm. One 

 of the polyps is 2 cm. long to the tentacles, and the tentacles are 



