88 Proceedings of the Royal Irish Academy. 



" The axis is calcareous, rigid, and brittle ; it is slightly oval in section ; 

 but in the younger portions it becomes quite cylindrical, and tapers till it is 

 thread-like. It shows a very white core surrounded by a brownish cortex." 



The polyps are disposed in two longitudinal series on opposite faces, 

 each of which consists of from two to four irregularly alternating rows. The 

 verrucae are low and truncate ; when retracted there is a deep depression in 

 the centre which is directed slightly upwards. This gives a very characteristic 

 appearance (fig. 62). They are about 0"4 mm. in height and 1'5 mm. in 

 diameter at the base. 



The spicules are extremely characteristic, and quite unlike those of any 

 other species (fig. 6.3). They consist of the following types, with measure- 

 ments, length by breadth, in mm. 



(a) Double-clubs with almost hemispherical heads, and with a relatively 



long constriction. On either side of the constriction the large 

 warts are arranged in a whorl, while beyond this there is a very 

 warty hub which gives the whole head a very irregular outline : 

 08 X 04; 0-07 x 0-035. 



(b) Smaller double-clubs in which the whorl is not so pronounced : 



0-07 X 0-46; 0-07 x 0-042. 



(c) A peculiar type, which approximate to capstans with terminal warty 



projections : 0-08 x 0-04 ; 0-07 x 0-021. 



(d) Elongated double-clubs with a long, narrow constriction, with the inner 



warts arranged appro.ximately in a whorl, and with more or less 

 elongated and irregularly warted hubs: 0-114 x 0-053; 0-114 

 X 0046; 0-095 x 0-05. 



(e) Double-spindles (some of these approach spindles). The ends are 



almost conical, and are variou.sly covered with very irregular warts 

 which gi\-e the whole a very ragged outline : 0-125 x 0-038, 

 0-11 X 0-03; 0-1 X 0-027. 

 Locality. — Bay of Bengal, 88 fathoms. , 



XXIII. Scirpearia alba (Thomson and Henderson), iigs. 64 and 65. 

 Scirpearella alba Thomson and Henderson, xl., p. 82, PI. ix., fig. 15. 



This species was established for tliree long, incomplete specimens, of a 

 white colour, 28, 411, and 408 mm. in length, with a corresponding diameter 

 at the lower end of 1-75, 2-3, and 1-75 mm. 



Two of the colonies are unbranched ; but the largest branches at a distance 

 of 251 mm. from the lower end. 



The axis is cylindrical, hard, brittle, and very 'calcareous, but becomes 



