58 PROCEEDINGS OF THE ACADEMY OF [Feb.,. 



equally developed, but one is longer, stouter and more branched 

 than the other. Dorsal and lateral surface of arms covered by a 

 thick skin, which is very finely and closely granulated; granules, 

 irregular in size and roughly distinguished as of two kinds; finer 

 ones entirely covered by skin, flat, irregularly polygonal, forming 

 together a sort of mosaic; coarser ones, coarser than any granules 

 of disk, hemispherical, tubercle-like, and uniformly scattered. 

 Ventral surface of arms apparently smooth, but covered by a mosaic 

 of flat and irregularly polygonal granules of microscopic size. First 

 pair of tentacle pores distinct, opening in slight depressions; second 

 often distinct; following three or four pairs entirely invisible; those 

 beyond are again distinct. Arm spines absent on proximal joints, 

 but occur from fourth or fifth bifurcation outwards. They are 

 exceedingly minute and granule-like, two to four of them occurring 

 at each tentacle pore. The double rows of hook-bearing granules 

 are present only on very fine twigs, the main stems within four- 

 teenth or fifteenth bifurcation being free from them. The shaft 

 between the first and second bifurcations usually consists of four 

 arm joints; the outer shafts consist of six to eight, usually seven 

 joints. Color in alcohol, as well as when dry: dark grayish brown 

 above, and dark yellowish brown below. 



Two specimens; off Misaki Marine Biological Station; 5-10 

 fathoms. Four specimens; Sagami Sea. 



Among the five known species of Astrohoa, A. clcwata (Lyman) is 

 distinguished from the others by the spiny granules of the disk and 

 arms, and A. globifera (Doderlein) by the position of the madreporic 

 shield. A. nuda (Lyman) and A. nigra Doderlein have distinct 

 annulations of hook-bearing granules on the arms throughout, while 

 A. ernos Doderlein has no such annulations on the greater proximal 

 part of the arms. So that the present species is near A. ernce, but 

 differs from it in the much finer and less distinct granules of the disk 

 and arms, and in the less numerous arm joints composing a shaft. 

 In the last character, A. arctos rather resembles A. nigra from 

 Zanzibar and from Hirado Strait. 



This species is common in the shallow waters around Misaki, 

 occurring together with Astrocladus conijerus, especially var. dofleini 

 [A. dofleini Doderlein is, in my opinion, conspecific with A. coniferus 

 (Doderlein), being, however, a variety of the latter]. According to 

 present knowledge, Astrohoa is represented in the Sagami Sea by 

 A. globifera and the present species, in deep and shallow water 

 respectively. 



