ASTEROIDEA i6i 



while the connecting, secondary plates have i or 2 smaller spinelets o-S-o-g mm. long. 

 These are all encased in a soft but pulpy sheath which gives them the appearance of 

 conical papillae. Koehler described the abactinal spinelets of hirsuta as being cylindrical 

 in the proximal part but flattened in the distal half (also pi. 66, fig. 2). In koehleri the 

 spinelets are not at all flattened distally. They are roughly clavate in form. Each spinelet 

 is built of rather numerous radiating irregular longitudinal laminae, coarsely denticulate 

 as shown in Fig. E, 2b. 



The inferomarginal plates define the ambitus and carry 2-4 spinelets (similar to 

 abactinal) in a transverse basally webbed comb. The plates are fundamentally 4-lobed 

 but are often irregular. The superomarginals are discernible only in a cleared prepara- 

 tion and then cannot be followed satisfactorily proximal to middle of ray. On the outer 

 half of ray the superomarginals, inferomarginals and adambulacrals form 3 adjacent 

 series. Superomarginal spines similar to abactinals. 



The extensive actinal intermediate areas are characteristic of the genus. The plates are 

 generally monacanthid, the spaced spinelets forming transverse series between adam- 

 bulacral and inferomarginal combs but with some irregularities. The innermost spine of 

 the actinal series may be joined to the outer adambulacral spine by a shallow web 

 (Fig. E, 2c, AC). 



The adambulacral armature is a transverse series of 3 or 4 subambulacrals and i 

 furrow spinelet. Fig. 2 c shows the armature of the sixth plate of type (adoral face) while 

 Fig. 2 J is drawn from an excised plate (aboral face). The innermost subambulacral spine 

 of consecutive series is involved in an inconspicuous contracted web which runs the 

 length of furrow margin, above the furrow spine, and is homologous with the often 

 conspicuous membrane between the innermost subambulacral spines of Othilia and 

 Echinaster. It is indicated in Fig. zc, but disappears in dried specimens. 



Mouth -plates: deep in furrow a spinelet similar to adambulacral furrow spinelet; 

 on furrow margin 3 or 4 webbed spinelets, the web continued to first subambulacral 

 (and less conspicuously along furrow margin). Subambulacrals, 4-8 in each angle, 

 either webbed in 2 series or variously joined to marginals. 



Madreporite very inconspicuous, situated \r from centre of disk, and surrounded by a 

 variable number of spinelets. 



Gonads, with short lobes, attached interradially on a level with the inferomarginal 

 plates, the duct opening below the inferomarginals in actinal interradial area. 



Type locality. St. 190, Bismarck Strait, Palmer Archipelago, 93-130 m., i specimen. 



Specimens EXAMINED. St. 181. SchoUaert Channel, Palmer Archipelago, 160-335 i"-' 

 mud, I specimen. St. 363. Off Zavodovski Island, South Sandwich Islands, 329- 

 278 m., 8 specimens. 



Distribution. Known only from Palmer Archipelago and South Sandwich Islands, 



93-335 m- 



Remarks. The specimen from St. 181 has the disk strongly arched and the bases of 



the rays drawn together to form a brood chamber in which, close to mouth, were a few 



eggs measuring 3-4 mm. in diameter. 



