496 



s. GOTO 



af 21 ; Foilioldet er altsaa omtreiit 

 som 1 : 2}. Armeue ere temmelig 

 smjrkki-e med trekautet Gjennemsnit. 

 Stjeiiifns midtei-sto Deel optagcs af 

 5 höie og staïrke kegledannede l'iggi;, 

 som i |- af deres Lseiigde ere beklce- 

 dte med flade Koni, der opad mod 

 deres övre Graendse blive stedse storre 

 og fladere og aiitage Form af kantede 

 Tavler ; ^sed Gnuideu af de 3 af 

 disse kegledannede Taarne er der 

 ndvendig en lignende tyk, men kort, 

 vaudret Pig. Hele dette Central- 

 parti hsever sig op o^er Armene og 

 sammenlignes ikke npassende med 

 en i Knndepunktet af 5 Bjergiygge 

 opfert Borg. Kj'gtavlerne danne kini 

 8 Piaekker paa liver Arm, en bredere 

 i Midten og en smallere paa liver 

 Side. Der er 4 lange Porefelter paa 

 liver Ai'm, nemlig paa liver Side eet 

 ovenover Kandpladerne og eet under 

 den midterste Tavlera^kke, adskilte 

 ved en sammenliaeugende Tavleraekke. 

 Disse store Porefelter ere selvfölgelig 

 egenlig opstaaede ved en Sammen- 

 smeltning af mange mindre, men oplöse 

 sig kiui mod Armenes Spidse i saa- 

 danne mindre Gnipper paa nogle faae 

 Porer. Foniden disse er der kiin 5, 

 af Hudskelettets Masker adskilte, 

 mindre Porefelter indeni ' Borgen,' 

 samt eet paa liver af dennes Sider, 

 naar undtages den, livor Madrepor- 

 pladen fîudes. Aile disse Porefelter 

 ere beklsedte deels med smaae Pedi- 

 cellarier, deels med finere Kom end 

 de, som bedsekke Hndskelttet, af 

 livilke Pandpladerne, Bng-tavlerne og 



Tlie smallest example (A) lias a 

 gi'eater radins of 55 mm, a smaller 

 of 21 ; the ratio is therefore nearlv 

 as l:2i. The arms are somewhat 

 slender and triangular in cross sec- 

 tion. The central pai-t of the star 

 is occupied by 5 high and stout 

 conical spines, which are covered 

 I of their length, with flat gi-ains 

 W'liich become constantlv larger and 

 flatter toward the upper limit and 

 assume the form of polygonal tablets ; 

 near the base of three of these conical 

 towers there is on the outside a simi- 

 lar tliick, but short horizontal spine. 

 The whole of this central part is 

 raised above the arms and may be 

 compared not improperl}' with a castle 

 raised at the nodal j)oint of 5 moun- 

 tain crests. The dorsal plates form 

 only 3 rows on each arm, a broader 

 one in the middle and a narrower 

 one on each side. There are 4 long 

 pore-areas on each arm, namely one 

 on each side above the marginal plates 

 and one under the median row of 

 plates, separated by a continuous 

 series of plates. These large pore- 

 areas of course reall}' result from a 

 coalescence of many smaller ones, but 

 resohe themselves into similar smaller 

 gi-oups with a small number of pores 

 only near the apex of the arms. 

 Beside these there are only 5 smaller 

 pore- areas inside the 'castle,' separa- 

 ted by the meshes of the dernaal 

 skeleton, with one on each of its sides, 

 with the exception of that in which 

 the madreporic plate is found. All 



