REPORT ON THE HEXACTINELLIDA. 333 



sists of irregularly united fibres, reticulated beams, with interposed irregular spaces and 

 passages, the outer orifices of which are covered by a dermal membrane. In addition 

 to the regularly disposed dermal jjentacts or hexacts there are scopul* with knobbed 

 branches. The parenchyma contains, besides uncinates, scopula-like spicules, each of 

 which is provided with one prolonged principal ray, which runs out to a fine point. 



1. Cyrtaulon sigsbeei, 0. Schmidt (PI. XCII. fig. 9). 



Since I am inclined to believe that the description which (J. Schmidt {loc. cit., pp. 

 58, 59) has given of his Volvulina sigsbeei was based on specimens of difi"erent species, 

 I must, in regard to the minute structure, restrict myself in the first instance to that 

 specimen of which only a fragment is available, as represented from a photograph in 

 PI. XCII. fig. 9. For an account of the more macroscopic characters I must simply refer 

 to 0. Schmidt's results. 



We have here to deal with very variously shaped, often goblet-like specimens, whose 

 wtill consists of an irregular feltwork, with anastomosing cavities both on the external 

 and on the internal bounding surface, covered over by a porous skin. 



The dictyonal framework consists of tuberculate beams, in which the nodes of inter- 

 section are here and there, and especially near the surface of the body, thickened and 

 beset with wart-like elevations. 



The parenchyma contains uncinates with central thickened nodes, and scopula-like 

 spicules with several thin prongs radiating out from the terminal knob of the stalk, and 

 bearing marginally-toothed terminal discs. The dermal skeleton consists of pentacts 

 and hexacts, and also of scopulae with knobbed prongs. 



As to localities, 0. Schmidt mentions (1) Barbados, 100 fathoms; (2) lat. 32° 9' N., 

 long. 82° 23' W., 158 fathoms ; (3) Morrolight, 292 fathoms ; (4) St. Vincent, 124 fathoms. 



2. Cyrtaulon solutus, n. sp. (PI. XCII. figs. 1-8). 



Among the numerous Hexactinellida which were obtained by the Challenger at Station 

 192 (lat. 5° 49' 15" S., long. 132° 14' 15" E.), near Little Ki Island, from a depth of 140 

 fathoms, on blue mud ground, there is one dried specimen which grew in the tubular cavity 

 of a piece of limestone, and which had the form of a cylinder 5 cm. in length and 2 cm. 

 in breadth. As may be observed in the sketch given on PI. XCII. fig. 1, the dictyonal 

 framework passing through the body consists of irregularly united flat or rounded beams 

 from 1 to 2 mm. in thickness, which surround interspaces and passages from 3 to 4 mm. 

 in breadth. As may be clearly recognised in some parts of the surface which have been 

 specially well protected by the surrounding stone, the whole was covered by a cylindrical 

 mantle-like veil, which exhibits in the dried state a square-meshed network with large 



