REPORT ON THE HEXACTINELLIDA. 345 



rectangular hexradiate, smooth, long and slender, radii subclavate. Retentive spicula 

 trifurcated attenuato-hexradiate stellate, minute and very numerous. Gemmules mem- 

 branous, aspicular." " Colour unknown in the living state. Hab. — Barbados (Dr. 

 (Cutting) Martinique, M. Plec, 1829. Examined in the skeleton state." 



Of the genus Iphiteon — a name which Bowerbank has ascribed to Valenciennes,' — 

 Bowerbank accurately described five species in 1869,' namely, I'phiteon ^xt/ricect (Val- 

 enciennes), Bowerbank, Iphiteon heatrix, Gray, Iphiteon suhglohosa, Gray, Iphiteon 

 ingalli, Bowerbank, and Iphiteon callocyathes, Gray. 



The essential characters of the first species, Ip>hiteon panicea, are established by 

 I'owerbank from a specimen obtained at Porto Rico, and preserved in the Museum of 

 the Jardin des Plantes, Paris. The diagnosis reads as follows :" — " Sponge cyathiform, 

 slightly pedicelled. Surface of rigid skeleton even. Oscula, pores and dermal mem- 

 l>rane unknown. Skeleton symmetrically radial, radii short and stout, areas of the rete 

 mostly six-sided spaces, within triangular ; fibre cylindrical, incipiently spinous. Tension 

 spicula simple, hexradiate, slender, abundantly spinous, radii terminally more or less 

 clavate. Rententive spicula spinulo-pentafurcated hexradiate stellate, few in number. 

 Gemmules simple, membranous, subspherical, irregularly disposed, very numerous." 



The second species, Iphiteon heatrix, Bowerbank, resembles Aphrocallistcs heatrix. 

 Gray, and has already been referred to in detail under the genus ApthrocaUistes. 



The third species, Iphiteon suhglohosa, Bowerbank, agrees with Dactylocalyx 

 suhglobosa, Gray. Bowerbank diagnoses this form* as " a massive sponge, somewhat 

 cyathiform, sessile ; surface uneven. Oscula and pores unknown. Dermal membrane- 

 retentive spicula spinulated biternate minute, very numerous. Skeleton symmetrical 

 radial ; areas confluent, somewhat irregular, mostly six-sided, spaces within triangular. 

 Skeleton fibre at the external surface coarsely and irregularly tuberculatcd ; disposition 

 of the tubercles sublinear. AuxiHary fibres rectangulated hexradiate, abundantly 

 spinous ; radii spinulated. External defensive spicula fusiform acerate, very large and 

 long, distal terminations occasionally incipiently spinous. Interstitial spicula rectangu- 

 lated hexradiate, very slender, radii subclavate, basal ray very long. Spicula of the 

 membranes retentive spicula spinulo-quadrifurcate and pentafurcate hexradiate stellate, 

 numerous ; margins of the spinulate terminations crenulate." 



The fourth species, Iphiteon ingalli, Bowerbank, agrees, according to Bowerbank 

 himself, with Dactylocalyx pumicea, Gray, which is said to be distinct from Dactylocalyx 

 jmmiceus, Stutchbury. Bowerbank gives the following diagnosis*: — " Sponge cup-shaped. 

 Rigid skeleton ; upper or exhalent surface with large intermarginal excurrent canals 



» Valenciennes never really diagnosed a genus Iphiteon. The only foundation for this supposition is a preparation 

 iu the Museum of the Jardin des Plantes in Paris bearing a label as above. He cannot be referred to as the founder 

 of the genus. 



2 Proc. Zool. Soc Land., 1869, pp. 323-357. ^ Loc. cit., p. 324. 



* Loc cit., p. 329. ^ Loc cit., p. 321. 



(ZOOL. CHALL. £Xr.— PART LIII.— 1887.) Crgg 44 



