BY R. VOX LEXDEXKELD, PH.D. 899 



Leucosolenia poterium. Polejaeff. 



Report on the Calcai-ea. Zoology of the Toy age of 

 II. M.S. Challenger. Part XXIV., p. 35. 



Spicules differentiated, of unequal size. The spicules on the 

 surface form a dermal membrane, consisting of several layers of 

 spicules, with thick rays, .which are only 6-8 times as longas thick. 

 The spicules of the inner surface with slender rays, which are 16-20 

 times as long as thick. The dermal spicules 1-2 times as long, but 

 3-4 times as thick as those near the inner surface. Gastral cavity 

 not fan-shaped. 



It appears in the Auloplegma form, and possesses peculiar 

 triradiate spicules in the peristomial membrane. 



Interior spicules with rays 0*12 — 0T8 x - 006 — 0*01 mm., 

 dermal spicules 03 x - 035 mm. Some Sub-dermal spicules show 

 an incipient fourth ray. 



Special description and figures in Polejaeff, I.e. 



Colour : White and yellowish. 



Locality : Australia (St. Vincent's Gulf, Wendt 1 Sydney, 

 Sonder? Bass' Straits, Wendt. Station 163, April 4, 1874. Lat. 

 36 3 50' S. long., 150° 30' E., off Twofold Bay; depth 120 fathoms, 

 Challenger); South America (Tour Bay, South-west Chili, Alert. ) 



3, SPECIES. ASCETTA CHALLENGE PJ. Von Lendenfeld. 



Leucosolenia Challenged N. Polejaeff. Report on the Calcarea. 

 Zoology of the Voyage of H.M.S. Challenger. Part XXIV., 

 p. 38. 



A special set of triradiate spicules covering the outer surface of 

 the colony. These are all sagittal, while the triradiate spicules of 

 the interior are all regular. Solemiscus form. The diameter of 

 the tubes varies from 0*3 — - 8 mm. ; the pseudopores are still 

 narrower, rarely exceeding 0'28 mm. in diameter ; the Oscula 

 sparsely scattered here and there possess the same dimensions, or 

 they are slightly larger. The whole forms an irregularly oval body 

 30 mm. long and 20 mm. broad in its thickest part, presenting a 

 compact web of minute tubes and terminating in a short (2 mm ) 

 peduncle, which is solid. 

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