112 



ZOOLOGICAL COLLECTIONS MADE DURING [Jan. 4, 



Pores. The dermis is not sufficiently well preserved to show 

 them. 



Hab, Portland Ba)', Chili (in the channel between the chief island 

 of the Madre-de-Dios archipelago and the mainland), 10 fathoms. 



Obs. The nearest identifiable ally of this Sponge appears to be 

 that described by Schmidt' as Siphonochalina bullata, which, as 

 already observed, it probably resembled closely in external characters. 

 It is not certain that that Sponge is identical with the Callyspongia 

 bullata of Duchassaing de Fontbressin and Michelotti ; and it cer- 

 tainly is not the Spongia bullata of Lamarck, which those authors 

 consider their Sponge to be. The chief distinguishing characters of 

 the two Sponges are as follows : — 



Siphonochalina fords 

 (Chili). 



External Characters. 

 ''Form tubular, perhaps 

 rising from an en- 

 larged base. 



S. bullata, Schmidt 

 (?Duch. et Mich.,non j 

 Lamk.), (West In-' 

 dies). 



{ Several tubes rising 



from one base. 



Main Skeleton. 



Network open. Two 

 sets of fibres regu- 

 larly arranged at 

 right angles ; fibres 

 from '07 to 'lis mm. 

 in diameter. 



Network close. Two 

 sets of fibres regu- 

 larly arranged at 

 right angles ; fibres 

 from -0355 to -1065 

 mm. in diameter. 



Spicules, 

 Acerate, tapering ab- 

 ruptly. Size -07284 

 by -0079 millim. 



Acerate, tapering ab- 

 ruptly, size '076 by 

 •025337. 



Cladochalina armigera, Schmidt (nou Duch. de Fontbressin 

 et Michelotti), var. pergamentacea, nov. (Plate X. fig. 4.) 



Cladochalina armigera, O. Schmidt, Spong. atl. Geb. p. 3.t. 



A fine dried specimen appears to represent this species, although 

 it shows some important differences from it. 



External Characters. Suberect, elongated, flattened from side to 

 side, the long diameter being about three times as great as the short 

 diameter ; the upper of the two edges bears most of the vents. It 

 is curiously bent to form an angle of 60° at about its middle, so that 

 the apex nearly touches the rock on which it stands. Surface even 

 except near the vents, and smooth, though finely striated by a sub- 

 dermal and a dermal network of coarser and finer fibres respectively. 

 Colour pale brown. Vents subcircular, long diameter from 1"5 

 to 3 millims., occurring at intervals of 8 to 15 millims. along the edges 

 of the Sponge ; they stand out on small rounded eminences to a 

 height of about 1 millim. from the surface, and end in a reticulated 

 bottom at from 2 to 4 millims. below the edge. Fores 1 



Main Skeleton. Composed of a vertical (" deep ") set of strong 

 horny fibres, of •04434 millim. average diameter, coming from the 

 centre, giving off numerous smaller branches laterally, and meeting at 

 right angles a stout (" subdermal ") set of fibres, diameter '056 to 

 •14 millim., which run along parallel with the surface, branching 

 and anastomosing so as to form the coarser meshes of the surface, 

 and have a tetra- to polygonal outline. Thesubdermal network forms 



1 Spong. atl. Geb. p. 33. 



