96 s, GOTO : 



are not very conspicusous, being dorsoventrally flattened and overlaid by 

 membrane. Although LuDWiG^^ states that they are absent from his speci- 

 mens (Panama region), I think he must have overlooked them. They are 

 very easily seen if a portion of the ray is treated with caustic potash solution. 

 Tliey are present in a specimen examined, from station 3307, from the great 

 depth of 1,033 fathoms. I also dissected a specimen from station 2452, off 

 NewfoundLmd, 89 fathoms, and the superambulacral ossicles are present. 



" In the centre of the conical abactinal x^i'oloi^gf^-^ion one can easily 

 distinguisli in many specimens a small ' pore ' evidently connecting with the 

 body cavity. This is also present in many Ercmicaster tenebrmius, and is 

 what Sladen took to be an anus in PorceUanaster. I think it must be an 

 artificial opening caused by a stretcliing of the abactinal membrane at the 

 summit of the cone, and possibly subsequent wearing, as the rudimentaiy 

 paxillfe are usually more or less worn down here. 



" The walls of the stomach contain nmnerous small straight or irregular 

 rods and gi-aius from 0.01 to 0.175 mm. in leng-th. They are sometimes 

 provided with in-egularities on sides or are irregularly triradiate. Thej' are 

 found also in the walls of the hepatic cœca, but are not so numerous. On 

 the hps of the peristome they are transformed into broader irregular flattened 

 rods with a few perforations, but in the peristome itself are comparatively 

 few scattered rods like those of stomach walls, and only near the lip they 

 are perforated. In the walls of stomach near mouth the rods are usually 

 simple and veiy regular, and tend to an-ange themselves in close meridional 

 series. 



"Japanese specimens. — ^I have eight specimens from station 4818, Sea of 

 Japan, 225 fathoms. One of the largest of these is figm-ed. All liave very 

 small low x^axillœ with comparatively few spinelets. The superomarginals 

 are also sHghtly nan'ower than in shallow- water Alaskan examples, but about 

 as in specimens from 1,033 fathoms, Bering Sea. (The latter have large 

 paxiUaB, with usually liigh pedicels, which lack entirely' the central si^inelots). 

 The Japanese specimens have four, but occasionally also three and five 

 fmTow spines. 



1) " Mem. Mus. Comp. Zoöl., vol. 32, ;1905, p. 105." 



