1915.] NATURAL SCIENCES OF PHILADELPHIA. 77 



Aspidophiura watasei sp. nov. It stands rather between Antho- 

 phiura and a certain group of Amphiophiura with very conspicuous 

 ventral interbrachial plates. 



Aspidophiura watasei sp. nov. 



This species is very near A. Jorhesi, but differs from it chieflj' in 

 the presence of a central boss to each of the six primary plates, in 

 the smaller radial shields, whifch are about as large as the radial 

 plates, in the ventral arm plates, which more rapidly diminish in 

 size outwards, in the longer arm spines, which are longer than half 

 the corresponding arm joint, and in the absence of tentacle scales 

 beyond the disk. 



The present species differs from A. minuta chiefl}^ in the presence 

 of a central boss to each of the six primaries, in the smaller radial 

 shields and in the better-developed arm combs. 



The type specimen is 5 mm. across the disk with arms probably 

 about twice the disk diameter, and 1.3 mm. in width. Color in 

 alcohol: disk yellowish gray above and white below; arms white. 



One specimen; Sagami Sea. One specimen; Uraga Channel. 



AMPHIOPHIURA gen. nov. 



Disk high, often convex, covered with plates and scales, among 

 which the primaries are very prominent. Radial shields stout, 

 joined in pairs. Arm combs and genital papillae present. Oral 

 shields oval, pyriform or trefoil. Second oral tentacle pores open 

 more or less, or entirely, outside oral slits; large, guarded by numerous 

 scales. Arms moderately long, gradually tapering outwards, with 

 blunt tips. Dorsal and ventral arm plates fairly well developed; 

 successive plates in contact with each other at least on proximal 

 arm joints. Lateral arm plates high, with few to numerous short, 

 peg-like arm spines. Tentacle pores large, with numerous scales. 



This new genus includes Ophioglijpha bullata Wyville Thomson, 

 which is here designated as the genotype; also the following species 

 with very conspicuous oral shields, which almost cover the ventral 

 interbrachial areas, 0. convexa Lyman and 0. insoUta, improba, and 

 ahclita, of Koehler; also the following species with very conspicuous 

 ventral interbrachial plates, 0. solida and scutata of Lyman, 0. 

 stellata Stucler, 0. paupera, sordida, liberata, urbana, remota, and 

 latro of Koehler, and Ophiura cediplax and pompophora of H. L. 

 Clark; also the following species with the ventral interbrachial 

 areas covered with many scales and having quadrangular ventral 

 arm plates, Ophioglijpha sculptilis ( = 0. variabilis) lacazei, lapidaria^ 



