REPORT ON THE ASTEROIDEA. 559 



The abactinal surface is beset with small narrow plates which are arranged in longi- 

 tudinal and transverse lines, forming an open network with regular square meshes. In 

 some places there appear to be indications of cruciform plates at the intercrossing parts, 

 but I am unable to say whether such plates really occur, or the resemblance is only super- 

 ficial and due to partial anastomosis of the plates at the crossing. Small, isolated, micro- 

 scopic spinelets with denticulate tips are borne on the abactinal plates, usually one at each 

 decussation, and sometimes one midway on the transverse trabecular The meshes are 

 covered with membrane, which is crowded with rather large, uniform, forcipiform pedicel- 

 lariae. These are so numerous that they mask altogether the papulae and give a general 

 semicrystalline granular appearance to the surface, when examined with a magnifying- 

 glass of low power. 



The marginal plate3 do not appear to be in any way differentiated ; and the uniform 

 crowding of pedicellarias extends up to the adambulacral plates. 



The adambulacral plates are very small, and their armature consists of two rather 

 elongate subequal spinelets, placed one behind the other and slightly obliquely. They 

 are covered with membrane, which on the spines near the mouth forms a more or less 

 saccular sheath. 



On the inner half of the ray, at the base of the innermost spine, on the margin of the 

 ambulacral furrow, there may be seen here and there a very small pedicellaria, which I 

 believe to be forficiform in type. It is, however, much smaller than the forcipiform 

 pedicel larias, which are so numerous on the test generally, and appears to be more or less 

 aborted in character. 



The madreporiform body, which is very small and difficult to distinguish, is situated 

 near the margin of the disk, and its surface is marked with only two or three simple 

 farrows. The ambulacral tube-feet are arranged in simple biserial series. 



Colour in alcohol, a dirty ashy grey. 



Locality. — Station 145. Off Marion Island. December 27, 1873. Lat. 46° 43' 0"S., 

 long. 38° 4' 30" E. Depth 140 fathoms. Volcanic sand. Surface temperature 41°-0 

 Fahr. 



Remarks. — This is a true Pedicellaster, and differs in no way from the structural 

 characters of Pedicellaster typicus. The presence of forficiform pedicellarise is, however, 

 an anomaly in the genus, which has been considered to possess only one kind — the 

 forcipiform. The representatives of the forficiform pedicellariae in Pedicellaster hypernotius 

 are so small and have such an aborted character that I do not consider their presence 

 sufficient to justify the removal of the form under description from the genus. In my 

 opinion, they give additional interest to this species as representing either rudiments of 

 organs more typically developed in an ancestral form, or incipient stages towards the higher 

 development of this form of pedicellaria as found in other allied Asterids. 



Pedicellaster hypernotius is more nearly related to Pedicellaster typicus and Pedicel- 



