REPOET ON THE HEXACTINELLIDA. 85 



phoenix, I may here note that the representation of the fine transversely arranged 

 prickles on the extremities of the terminal rays has not Ijeen successful. 



The floricomes which are attached to the tips of the dagger-shaped hypodermalia 

 differ from those of Ewplectella aspergillum in their somewhat greater size and stronger 

 terminal rays, as well as in the longer claws of the terminal plates ; they thus more 

 nearly resemble those of Euplectella suherea (PL XIII. fig. 4). 



Since no specimens of Regadrella i^hcenix occur among the HexactineUida collected 

 by the Challenger expedition, I have figured (PL XIII. fig. 1), from a photograph, a 

 specimen which was kindly given to me for examination by Professor Oscar Schmidt. 



The localities for this species, as at present known, are, according to Oscar Schmidt, 

 the Barbados, in 221 and 288 fathoms of water, and Santa Cruz, in 248 fathoms, in the 

 Gulf of Mexico. 



Subfamily 2. Holascin^ (PI. XIV. figs. 6-13; Pis. XV.-XIX.). 



Euplectellidse in which the lateral wall is solid, that is, not perforated by parietal 

 gaps. The principal spicules are not fused together, and form with their longi- 

 tudinal and transverse rays a quadrate network. The hypodermalia are dagger-shaped, 

 and have a somewhat swollen distal ray beset with prongs, and frequently extended by 

 apposed pointed diacts, but in other cases probably bearing a floricome. The 

 hypogastralia are either simple pentacts without a proximal ray, or hexacts in which 

 the inward projecting (proximal) ray probably can bear a floricome. 



Genus 1. Holascus, u. gen. (PI. XIV. figs. 6-13; Pis. XV.-XVIL). 



Tubular in form, with a compact wall, the outer surface of which shows no pit-like 

 depressions, while a lattice-work of longitudinal and transverse ledges projects internally. 

 The upper transversely truncated extremity is provided with a thickened margin which 

 is destitute of a spicular wreath, and is closed by a compact sieve-plate, while the 

 inferior extremity runs out into a basal tuft. The network of strands which serves 

 for the support of the body-wall consists of greatly prolonged, longitudinal and trans- 

 verse rays of compact hexacts, pentacts or tetracts, which lie close to one another, 

 forming a tolerably firm framework, and which are also surrounded by a coating of thin 

 comitalia. 



In the parenchyma, in addition to various other spicules, oxyhexasters occur, or instead 

 of these in other cases fibulas. 



The sword-shaped h}T3odcrmalia bear no floricomes, but are externally extended by 

 apposed pointed and narrow diacts. 



