IOTBROIDBA OF Non'iii i'\< nic \m> ak.p m i-.nt w atkiis m-ih ~'.i 



groups Thej rather increase in number and size io\Minl the marginal spu 

 reaching a length of from l to l 25 mm. in the biggest specimens, and l nun in an 

 example with R. 170 nun. The form is broadly lanceolate t<> broadly oval, <>r even 

 subelliptical, more or less compressed, and the end >>f the jaws are either smooth 

 (station 3261 or are provided with one to five short, interlocking teeth ^ t i< >n 



3251), both being verj barge specimens In b slender rayed variety from Btation 



> and Btation 3518 the Btraight pedicellariae are fewer than normal. 



W'lmi might be called the typical arrangement <>f marginal unci acfanal Bpines, 

 if there were not so man] exceptions, is one Beries for each of the marginal rows, and 

 n single series oi actinal Bpines- three in all; or two series of actinal Bpines (proxi- 

 mally at least) in the largest examples four in all In three very lai 

 from station 3253 two have a single Buperomarginal spine (except sporadically 

 on the proximal two-thirds or three-fourths <>f ray, then a tram of two or 



three short tubercular Bpines; the third has mostrj two Bpines except at the v< 



of the ray whore there is one. and on the outer fourth or fifth where there is B tl 



series of four or five short tubercles; of the first two, one baa frequentl] 

 inferomargina] spines and but one actinal series, the second has one inferomargina] 

 spine to a plate and two actanaJ Bpines and plates of nearrj equal size; the 



third has occasionally two inferomargina] -pines, and two series of actinals, the 

 inner niueh the smaller. A Becond Buperomarginal spine, smaller than the primary 

 i- not uncommon, and even a third may be present in an otherwise typical specimen; 



station 3441. The distal plates \erv often have throe to five tuberelc-, hut may 



have only one. Irregularity in the number of infi inal spines is less common 



but occurs. The Buperomarginal Bpines are decidedly smaller than the doi 



onical, sometimes compressed, with pointed, blunt, or irregular tips, and fre- 

 quently are acorn-shaped distally. The mferomarginsls (and actinals also arc 



abruptly larger if the superomarginals are small, or subequal if they are large, of 

 much the same shape, mote or less elevate and slightly bent, the tips being blunt, 

 The Buperomarginal Bpines are provided with thick wreaths, and the inferomarginals 



and actinals with half-wreaths of crossed pedicellariae. with much Larger broadly 

 lanceolate to triangular-ovate Btraight pedicellariae scattered among them. The 



intermargina] and actinal channels are proximalrj (and also usually distall] armed 

 with stout, Btraight pedicellariae of the general form of the dorsals but la;_ 



rule, with typically broadened jaw- endue' in Beveral small curved teeth Some of 



the pedicellariae (as station 3520 bave the jaws nearly as broad as high, viewed 



from the hack, with parallel sides and gently curved margin armed with about five 



or si\ teeth. The] resemble somewhat the bivalved pedicellariae of Goniasteridae 

 The adambulacraJ spines stand two on a plate on the proximal half <>r two-thirds 



of ray, then they alternate one and two. The spines resemble those of act rvOto. 

 Alternate furrow spines arc more advanced into the furrow, and are slenderer than 

 the Bubambulacrals which in turn are much slenderer than the actinals The furrow 

 spines taper shghtly, while the others arc usually untapcred, subeylindrienl (or even 



clavate), sometimes n trifle Battened. All have large Bubterminal groups of tapered. 

 unequal Btraight pedicellariae. The Btraight pedicellariae arc toothless ami have 



narrow jaws viewed from the hack: rather aeutc-ovato from the side In 

 specimens there nre four pairs of contiguous adambulacral plates behind the mouth 



