PLATE XIV. 



Page 

 Fig. 1. HaUirhoa costata, Larax. A small three-lobed specimen from the Upper Green 



Sand at Warminster, Wiltshire. Natural size 67 



Fig. 1 a. The same. A conical, partially five-lobed, example from the same locality, showing 

 the stem and the root-like extensions at its termination. Natural size. 



Fig. 1 b. The same. A four-lobed specimen from Warminster, showing a partial division in 

 each of the principal lobes. Two-thirds the natural size. 



Fig. 1 c. The same. A vertical median section, showing the shallow cloaca and the course 

 of the larger canals opening into it. Natural size. 



Fig. 1 d. The same. A transverse section of a five-lobed example, taken below the level of 

 the cloaca, showing in section the larger vertical canals. Drawn from a polished 

 specimen presented to the Museum by Robert Etheridge, sen., Esq., F.R.S. 



Fig. 1 e. The same. Portion of the interior spicular mesh, enlarged sixty-four times. 

 Drawn from a transparent microscopic section by means of the camera lucida. 

 The small square to the left indicates the natural size. 



Fig. 2. HaUirhoa costata, var. brevicostata, ilich. From the Upper Green Sand at War- 

 minster. Two-thirds the natural size 68 



Fig. 3. HaUirhoa costata, var. elevata, Hinde. Two-thirds the natural size. From War- 

 minster 68 



