46 AGLAOPHENIA BISPINOSA. 



with the margin cut into rather shallow teeth, and wdth the cavity divided 

 into a distal and proximal portion by a distinct intrathecal ridge of a 

 sigmoid form. Supracalycine nematophores not overtopping the hydro- 

 theca ; mesial nematophore adnate to the proximal fourth of the hydro- 

 theca, becoming free only close to its point. 

 Gonosome not known. 



Dredged off Alligator Reef, from a depth of 110 fathoms. 



The remarkable sigmoid form of the intrathecal ridge constitutes a 

 very distinctive character of this species. Another striking feature is 

 found in the numerous well-marked septal ridges by which the inter- 

 nodes of the pinnae have their cavity divided into intercommunicating 

 chambers. It is a strong, rather rigid species, and attains a considerable 

 size ; but as the specimen had lost its hydrorhizal extremity, the entire 

 length attained by it could not be determined with certainty. 



In the absence of the gonosome its reference to the genus Aglao- 

 phenia is of course only provisional. 



Aglaophenia bispinosa. 

 Pis. XX VII and XXVIII. 



Trophosome. — Stem attaining a height of eight inches, stout, simple, 

 rising from an entangled mass of branching tubular filaments, fascicled 

 below, and presenting from distance to distance knot-like projections ; 

 pinnae alternate, attaining a lengtli of nearly an inch and a half. Hy- 

 dro thecae deep, widening upwards; margin with a single, strong tooth-like 

 process in front, and with short, blunt teeth in the rest of its extent ; 

 intrathecal ridge not conspicuous. Supracalycine nematophores stout, 

 not overtopping the hydrotheca ; mesial nematophores two in number, 

 the distal one adnate to the hydrotheca, along which it extends for 

 about one third of the height of the hydrotheca, the proximal one forming 

 a short, stout spine-like process just below the distal. 



Gonosome. — Corbulae open, formed by two alternate or sub-opposite 

 series of free, rib-like processes, each of which carries near its base a 

 small hydrothecal cup, and along its distal margin a series of numerous 

 tooth-like nematophores ; tiie rachis of the corbula continued towards 

 the common stem as a long peduncle carrying about five unchanged 

 hydrotheca\ 



1)it(1<xim1 oir Allij.'Htor Reef, from a depth of 15G fathoms, ^n<l otV Tcnnossoe R<of. from a d«'pth 

 of '2i»0 fathoms. 



