Nakkativk o>" Ijaiiama 1:^mm:diti()N. 79 



nent •• cobble-stones." and a still more prominent accessory 

 piece is placed in front of each side arm-plate, the latter being 

 considerabh- less conspicuous than the accessory piece. 

 There are two short. stubb\- arm-spines to each side arm- 

 plate, and a large tentacle-scale apparently soldered down to 

 the lower arm-plate, there being no visible tentacle-pores. 

 The mouth-pajMlhe are si.v on each side of each jaw. and they 

 too are apparenth' scjldered together, a character of the genus 

 Ophioniii^iuiu. Another interesting fact is that the arms roll 

 in a \'ertical plane, a feature heretofore. 1 believe, obser\-ed 

 onlv in the Astrophytid;v. or basket-tish. This resemblance 

 is further helped out by the prominent ridges on the top and 

 sides of the arms, these ridges not being formed by the upper 

 and side arm-plates. Indeed it is doubtful that this strange 

 ophiurian is an ()p/i/(>)jiits/'ui)i at all, and it may be regarded as 

 the first of a series of no less than eight species secured at 

 this station, which lead from the ti'ue serpent-stars on the one 

 hand to the true branched AstrophytidcV on the other. 



The species above described would seem to be on the 

 serpent-star side of the line, still retaining the characteristic 

 mouth-parts, i. e.. mouth-shields, side mouth-shields and mouth 

 papilke. combined with several features characteristic of the 

 Astrophvtidce. 



Next in our j-jrogress toward the typical basket-tish. we 

 come to a species of Sig'sbcia. with a highly vaulted disk 

 covered with harsh granules, and exhibiting jironounced 

 radiating ridges, and. in addition, raised ridges which form 

 concentric pentagonal markings, crossing the radiating ridges 

 at riirht aniiies. The bases of the arms are swollen, and the 

 arms throughout are ringed as in the next genus. The radiat- 

 ing ridges on the disk are formed not by radial shields, but by 

 series of nodules or small plates. The amis are harsh w ith 

 rough granules arranged in ridges as in the next genus, and 

 roll naturallv in a vertical plane, forming a stiff coil which can 

 hardh' be unrolled after the animal is dead without breaking 

 the arm. There are large and prominent accessory plates on 

 the sides of the arms. This species differs from S/g-sbc/ci 



