218 DR. HTNDE A"ND MR. HOLMES ON SPONGE-REMAIIS'S 



the preceding form ; above is a whorl of vertical laminae with 

 spined or dentate margins ; the apes is coQical, spined, with a 

 terminal spire. Length of spicule '058 mm., width of median 

 whorl "O-l mm., thickness of shaft '013 mm. 



The seven forms described above (PI. XI. figs. 17-23) are all 

 modifications of a common type which has an expanded base of 

 divergent sj)ines, a median whorl of horizontal spines, and an 

 upper or summit whorl of spines, whilst the apex is pointed or 

 obtusely spined, or of upright laminae. These spicules are distinct 

 in these details from the sceptrellas of any recent species of 

 Latrunculia. 



Latrunculia Oamaruensis,xx.^^. — PI. XI. fig. 34. Sceptrella with 

 stout, elongate, subf usiform shaft ; at the base are three or four 

 whorls of minute spines se^^arated by short interspaces, separated 

 from these by a smooth interval is a whorl of conical horizontally 

 disposed spines or processes, followed above by five other whorls 

 at irregular intervals. At the upper end of the shaft is a whorl 

 of curved spines or plates, and the apex is formed by a stout ver- 

 tical spine. The spines or processes of the whorls are armed 

 with secondary spines. Length of spicule "206 mm., greatest 

 width of whorls -OIjS mm., thickness of shaft "016 mm. 



PL XI. fig. 35. Sceptrella of nearly the same character as the 

 preceding, but the shaft is curved, the spined whorls are much less 

 regular and there are intermediate single spines, whilst the upper 

 end consists of a shallow cup-shaped expansion with a group of 

 spines at the apex, some of which have minute globular heads. 



This and the preceding form greatly exceed in size the 

 sceptrellas in any recent species ; they probably belong to the 

 same species, which may be provisionally named Latrunculia 

 Oamaruensis. 



Latrunculia (k). — PL XL fig. 36. Sceptrella with straight, 

 robust, subfusiform shaft, the base furnished with three whorls 

 of minute spines ; above these are five whorls of stout conical 

 processes, secondarily spined ; an upper whorl of curved spines 

 or plate-like hooks, and at the apex several projecting spines. 

 Length of spicule '133 mm., width across whorls '04 mm., thick- 

 ness of shaft '013 mm. In character this spicule resembles the 

 preceding, but it is much shorter. 



Latrunculia (1). — PI. XL fig. 37. Sceptrella with stout sub- 

 cylindrical shaft having four or five whorls of minute spines at 

 the base, succeeded above by three whorls of spines or processes. 



