TETRAXONIDA 



319 



Section CLATHRIEAE 

 Genus Clathria, Schmidt 

 Clathria papillosa, Thiele. 



C. papillosa, Thiele, 1905, p. 449, fig. 66. 



Occurrence. St. WS 81 : Falkland Islands, 81-82 m.; St. WS 83 : Falkland Islands, 129-137 m.; 

 St. WS 84: Falkland Islands, 75-74 m.; St. WS 88: Falkland Islands, 96-127 m.; St. WS 95: 

 Falkland Islands, 108-109 m- 



Remarks. Apart from the arrangement of the skeleton, all six specimens are typical, 

 except for negligible differences in the sizes of the spicules in two of them. The skeleton 

 is a regular network of triangular mesh, the sides of the meshes being one spicule length 

 only and composed of three to six spicules, with the acanthostyli confined to the nodes 

 of the network. In two of the specimens a slight departure from this arrangement is 

 found in that occasional fibres, formed of bundles of megascleres, are seen running 

 perpendicularly to the surface. The arrangement of the skeleton is therefore not only 

 more variable than is usual in the genus Clathria but is not very typical of that genus. 



Distribution. Calbuco. 



Clathria toxipraedita, Topsent. 



C. toxipraedita, Topsent, 1913, p. 620, pi. v, fig. 4, pi. vi, fig. 12. 



Occurrence. St. 144: South Georgia, 155-178 m.; St. 190: Palmer Archipelago, 93-13001.; 

 St. WS 33 : South Georgia, 130 m. 



Remarks. The larger chelae, described by Topsent, are absent from this specimen, 

 which agrees with the holotype in all other respects. 



Distribution. Burdwood Bank. 



Clathria lipochela, sp.n. (Plate LV, figs. 6-7; Fig. 29). 

 Holotype. B.M. 28. 2. 15. 352. 

 Occurrence. St. 51 : Falkland Islands, 105-115 m. 



Diagnosis. Sponge pedunculate, irregularly flabellate ; surface un- 

 even, porose; inhalant and exhalant openings not distinguishable as 

 such ; skeleton an irregular network of quadrate meshes in which stout 

 primary fibres may be recognized running vertically to surface ; fibres 

 containing much spongin, cored by principal megascleres and echin- 

 ated by acanthostyli; microscleres absent; principal megascleres 

 smooth styli, occasionally sparingly spined near base, 0-21 by 

 0-009 i''^'^-; echinating acanthostyli somewhat variable in size, with 

 spines evenly distributed throughout their length and slightly more , , j^ 

 numerous at base, 0-09 by o-oo6 mm. ; auxiliary spicules subtylostyli, ^. clathria 



smooth, straight, arranged in bundles at right angles to dermis or upochela, sp.n. 

 scattered singly among meshes of main skeleton, 0-15 by 0-003 "^i""- Spicules, x 300. 



