EEPORT ON THE HEXACTINELLIDA. 39.> 



Family 11. M e l i t t i o N i D ^, Zittel. 



Sponges in the form of a ramified tube or of a cup witli lateral blind diverticula. 

 The dictyoual framework forms very irregular meshes. The parietal skeleton is honey- 

 comb-like, with tolerably regular hexagonal, radially disposed canals, arranged at right 

 ansfles to the bounding surfaces. In each of these little canals the membrana rcticu- 

 laris, is continued in a funnel-shaped extension of the laterally disposed, glove- 

 finger-hke chambers, across the canalicidar lumen. The free outer surface is covered 

 with the dermal membrane, and the inner surface with the gastral. The gastral 

 skeleton is without scopula3. 



Single Genus Aphrocallistes, Gray. 



On the hexact dermalia the distal radial ray is more or less distinctly fir-tree-like 

 with a lateral coating of spines. Besides these there are dermal scopula;, in which the 

 prongs are usually knobbed, more rarely pointed. The parenchyma contains irregular 

 oxyhexasters, and in many cases also discohexasters. 



Species 1. Aphrocallistes bocagei, Perceval Wright. 



An elongated, almost tubular cup, a hand's length or more in height, with numerous 

 glove-finger-likc radial, and somewhat downward directed diverticula from the wall. 

 The lumen of the cup is traversed at considerable intervals by several loose lattice-w'ork 

 septa, which coiTespond in their insertion on the sides to the lateral diverticula, and 

 exhibit semicircular sections. The loose parenchymalia are represented by uncinates 

 directed at right angles to the bounding surface, and also by hexasters of different kinds. 

 Besides oxyhexasters with approximately equal principals and terminals, there are others 

 in which the axis is considerably elongated, and in which the two strong, more or less long 

 principal rays are divided at their extremities into four markedly divergent moderately 

 long terminals, while the four rays representing the two other axes remain, as a rule, 

 undivided. Small discohexasters occasionally occur. Corresponding to the dermal 

 hexact pinuli, there are on the gastral surface autogastral diacts of variable length, which 

 are more or less rough, especially on their rounded extremities. The dermal scopulse 

 possess, for the most part, four straight somewhat diverging prongs with pear- shaped 

 terminal knobs bearing lateral barbs. Besides these there are dermal scopula; with four 

 pointed rough prongs, and others with four strikingly long, rough prongs equipped with 

 small spherical knobs. Cape Verde Islands; Florida, 283 fothoms ; English Channel, 

 700 fathoms; coasts of Spain and Portugal; Antilles Islands, 1G4 to 400 fathoms; 

 Atlantic coast of France. 



