190 



"ENDEAVOUR" SCIENTJFIC RESULTS. 



a loose plexus or inter-reticuluni between them, and the mesh 

 is of irregular shape. The principal styli are usually slightly 

 curved ; the auxiliary styli are usually straight ; and the special 

 dermal styli are slightly subfusiform, usually curved, with the 

 curvature restricted to, or most pronounced in, their basal half. 

 The dermal styli are of very nearly the same size in all the 

 varieties, but, owing to the fact that spicules occur of all sizes 

 and shapes intermediate between them and the accessory styli, 

 it is impossible — at any rate in the present specimens, owing 

 to the damaged state of the dermal layer — to determine the 

 exact upper limits of their size. One can therefore only quote 

 the size below w hich they are usually to be found. The micros- 

 cleres offer no assistance in the discrimination of varieties. 

 The chelffi may differ slightly in different varieties, but since 

 they are also slightly variable in one and the same, the diffi- 

 culty of fixing upon their distinctive peculiarities is too great 

 to render them of service. The degree of torsion of the smaller 

 chelae is usually not more than qo^. The toxa appear to be 

 absolutely identical in form in the different varieties. They are 

 hair-like spicules usually with a central flexure of fairly definite 

 form, but otherwise extremely variable in shape. They would 

 seem to be capable of indefinitely continued growth, and in 

 some cases, at least, attain a length of more than 400 ;t. As 

 growth proceeds the arms become irregularly flexuous and 

 twisted in various planes, and in many cases the spicules lose 

 all semblance to toxa. The colour in the living condition of 

 all the varieties previously described is some shade of red ; 

 that of the new varieties is unknown. The colour in dry 

 specimens, is some shade of yellow or light brown. 



Rhaphidophlus tvpicus, var. proximus, var. nov. 

 (Plate xxviii., figs. 3, 4, and fig. 2>7-) 



Of this variety the museum possesses two specimens. Both 

 acf& stipitate, ramose sponges, with short and relatively stout 

 irregular branches, which divide frequently and often anasto- 

 mose, and are either restricted entirely to the one plane or 

 come to lie in overlapping planes. The branches are either 

 circular in cross section or compressed in the plane of branch- 

 ing, and measure from 6 to 10 mm. in their lesser diameter. 

 The two specimens are very nearly equal in size ; the slightly 

 larger is 90 mm. in height. The texture is denser than in any 

 other of the varieties here described. The main fibres are 

 rarely less than 80 \i in stoutness and often attain to from 

 120 to 150;*. Acanthostyles are fairly abundant; those which 

 echinate the fibres are often very deeply implanted in the 



