110 Mr. E. A. Smith on Species of 



Leptychastek, gen, nov. 



Discus 5-radiatus, compressus ; radii mediocriter elongati ; super- 

 ficies dorsalis fascicules pedunculatos coufertos spinarum minu- 

 tarum gerens ; radiorum latera serie unica tessellarum tenuium 

 transversarum lamellariurn, ad ambulacra haud productanim 

 munita; interstitia iuter tessellas et ambulacra spinarum parvarum 

 fasciculis ordinatim cum tessellis dispositis ornata ; tessella madre- 

 poriformis margiualis, in angulo interradiali sita. 



This genus shows more affinity to Luidia than to any other. 

 It cliiFers from it, however, in the lateral lamellar plates being 

 covered with minute spines not extending to the ambulacra, 

 in the absence of elongated spines, and the body being pro- 

 portionally larger than in that genus. 



Lej)tyckaster herguelenensis^ sp. nov. 



Discus 5-radiatus, mediocriter magnus, compressus, supra infraque 

 planus, latitudine radiorum longitudinis circiter |- sequans ; radii 

 sensim attenuati,basihaud latissimi; spinte ambulaerales graciles, 

 quaternis vel quinis sulcis transversae, intimis duobus longissimis, 

 caeteris sensim brevioribus ; oris anguli interradiales acuti, spinis 

 4-5 utrinque muniti ; radiorum latera et superficies iaferiores tes- 

 sellis transversis, angustis, lamellaribus (quae versus radiorum api- 

 cem fere ad spinas ambulaerales productse, sed basim versus ab illis, 

 spatium triangulare in angulo interradiali relinquentes, recedunt) 

 instructa ; hae tessellse spinis minutis scabris amictae, ad angulos 

 interradiales longissimae, et versus radiorum apices sensim decur- 

 tatse ; inter eas spinasque ambulaerales fere per radiorum longi- 

 tudinem totam series est unica fasciculorum parvorum spinarum 

 brevium, sed versus radiorum basim sunt sensim series secunda, 

 tertia et quarta, omnes ordinatim cum tessellis dispositse ; super- 

 ficies dorsalis fascicules pedunculatos confertos spinarum brevium 

 gerens ; tessella madreporiformis mediocriter magna, subovalis, 

 margiualis, in angulo interradiali sita, et spinarum fasciculis ob- 

 tecta. 



Disci diam. 23 millim., crass. 8 ; radiorum longit. 38, diam. ad 

 basim 13. 



The fascicles of little spines on the dorsal surface are raised 

 on short fleshy peduncles, and are very closely packed ; and 

 the madreporic plate is concealed by similar groups of spines. 



OpMuridsB. 



OpMacantha vivipara'^j Ljungman. 



The specimens from Kerguelen's Island appear to differ 

 slightly in a few respects from those described by Ljungman, 

 in the 'CEfversigt af Kongl. Vetenskaps Akad. Forhandl.' 1870, 

 p. 471. The habitat given (Altata,on the west coast of Mexico) 



