wi'KKoiui; \ in SORTS PACIFIC AND HXJACXNT \v.\TKi:s I l>HKlt 235 



The thick dermis is raised into conspicuous cauliflowerlike p which im 



spinelets and entirely obscure the skeleton. 



The genus is named in honor of I >r Rene* Koehler, "f Lyons, tin- leading authority 



on Antarctic echinodi i 



LYSASTEKIAS1 i-h.-r 



8 M ' 33, 



lug. 1908, p. 356 i* r 1891 : 



p 594; i ■ 197 



Analeriat Li dwio, L903, p L0; L920, p. 11; 



II \ t.uiiii i.. 1914, p 354 \ I Perrier, l y T 



• r, L875 



\ KUKII.I.. Sll.'lll. iW--. 191 I. P 



l.i n« : . K ■ ■ i ■ ■ 1920 i. 16 



Diagnosis. Marginal and abactinal skeleton much reduced, consisting of lateral, 

 spaced, transverse series or tongues of plates (composed of two reduced marginals 

 plus sometimes one or Beveral abactinals) abutting on the adambulacral plat 

 dorsal surface with much reduced, disconnected, scattered platelets; dermis thick, 

 surrounding the Bpinelets in mammillated pustules; adambulacral plates monacan- 

 t hid : no actinal spines, the plates if present extremely rudimentary; gonads open 

 centrally- paedophoric. 



This genus baa usually been incorrectly called Ai \ ■ 



Verrill's genus Paedastericu was founded pretty Largely upon an erroneous trans- 

 lation. Ludwig 1903, p. 12), in a sj aopsis of "Anasterias" says: "DieSpagenhaben 

 unit Ausnahme der Armspitzt Randstach* e Tatzenpedicellarien 



vorhanden • * • An. chirophora n. sp." Verrill diagnoses the genus: " * * * 



ipper marginal plates l><i:iLr absent except as rudiments distally." lint Ludwig 

 in ii major division of his synopsis states that the upper marginal plates are present 

 in chirophora. Koehler (1920, p. 30) has adopted Pa is, and added a new 



Bpecies, joffi 



Koehler finds in his Pa* ■■■•'■ i joj} abactinal cro s-bars of several piec< s, as 

 in / Ludwig); but he thinks that the Buperomarginals are not I 



found in these arcs Rather, they are one or two plates in the interbrachial ai 

 above the first inferomarginals, and quite independent of the little cross-tiers 

 the rays, where the Buperomarginal would consequently be lacking. In a specimen 

 of A which I have examined (No. 1842, Mus. Comp. Zo6l t 



" ant nun Iml niTnl " arcs consist usually of tun, sometimes three, plates; but the outer 

 usually iperomarginal is oriented transversely and the inner, nr infero- 



marginal, more longitudinally j u<t as in eh irophora, lactea, and perrieri. Koehler may 

 In- correct in bis interpretation of 1 1 1 « - lateral plates of joffrei and belgieae. But 1 

 think tlmt the outer of the t « o plates in the antiambulacral arcs of chirophora, la 

 and ./" rru n is to I"- interpreted as sup* The i> pe of Paeda U tally 



with thai of Lysasterias would possess superomarginals. The presence in bdg 

 nml sniilm of Beveral plates (instead of two) in each lateral arc probably represents 

 simply n less degenerate condition of the abactinal skeleton. In tentra one or two 

 small plates »r.' sporadically present above the relatively large, unmistakable, trans- 

 verserj oriented, Buperomarginal. These small plates are homologous with the addi- 

 tional lateral plates nf btHgicat It follows, therefore, that there is nothing character- 



