THE SPONGES OF THE WEST-CENTRAL PACIFIC 115 



The exterior color in life was brilliant orange. The interior was paler 

 and duller, almost drab. The color is maintained astonishingly long in alco- 

 hol. The consistency was strongly spongy, like a commercial sponge. 



The surface is verrucose, or wart-like, with projections up to 5 mm 

 high and 5 mm in diameter, separated from each other by meandering valleys 

 some 3 or 4 mm in diameter. This labyrinthine region is roofed over by a 

 thin protoplasmic dermis about 10 ( u thick. Underneath this roof is an ex- 

 tensive subdermal space, exactly as in the genus Hippiospongia. These warts 

 or islands, as described above, are in turn tuberculate or of granular surface. 

 Oscules cannot readily be found. The exhalant system doubtless makes use 

 of openings from the extensive subdermal space, but these openings are 

 very readily closed by the muscular cells in the dermis. 



The ectosome has been described in discussing the surface. The endo- 

 some consists primarily of a dense reticulation of clear fibers very much like 

 those in the genera Spongia and Hippiospongia. There is little space left 

 for the flesh, and particularly for the flagellate chambers, yet these are as- 

 tonishingly abundant, taking advantage of every interstice. They are spheri- 

 cal, some 30 ll in diameter, so that not only the fibers but also the flagellate 

 chambers closely resemble those which characterize the genera Spongia and 

 Hippiospongia. 



The skeleton consists of fibers which retain their elasticity when dry, 

 which is true of very few sponges but is true of the best commercial ones. 

 These fibers are chiefly of the type which has been regarded as secondary, 

 about 50 fx to SO /x in diameter. There are no obviously ascending fibers. The 

 one thing that separates this species from the genus Hippiospongia is the fact 

 that fairly abundantly scattered over the fibers, with the heads imbedded and 

 with points projected outward, are very characteristic megascleres. These 

 are acanthostyles with the spines in symmetrical whorls, about 12 to 18 such 

 nodes per spicule. The sizes range from about 10 ll by 170 [x to 14 ll by 



180 LL. 



This species was first described by Carter, 1883, page 310, as Ectyon 

 mauritianus, from the central Indian Ocean. It is characterized, as compared 

 to other species in the genus, by the comparatively large spicules. There is 

 a good deal of possibility that it should fall in synonymy to the species which 

 was first described as Alcyonium sceptrum by Lamarck, 1815, page 163, from 

 a locality not specified. 



Carter in 1885, page 316, described a sponge as Euspongia anfractuosa. 

 Lendenfeld, 1889, page 313, discussed this further, extending its range 

 throughout the Australian and East Indian region. According to the descrip- 

 tions of both Carter and Lendenfeld, this species is a typical Hippiospongia 

 but differs from others in that genus almost exclusively by its color in life, 

 which is described as bright orange. It is worthy of note that the obviously 

 proper echinating spicules of Agelas are very difficult to find in some sped- 



