232 ANATOMY AND PHYSIOLOGY 



FIG. 



25. OVO-SPINULATE. The basal inflation being oviform, 



the smallest portion being at the extreme basal 

 point. From Tetliea spimtlaria, Bowerbank. X 

 308 linear. 



26. EXORMI-SPINULATE. Having the spherical inflation 



slightly within the basal portion of the shaft of 

 the spiculum. Hymeniacidon celata, Bowerbank. 

 X 260 linear. 



. BISPINULATE. See No. 228, and Plate X, same 

 number. 



. TRISPINULATE. See No. 229, and Plate X, same 

 number. 



27. ENSIFORM. Expanding towards the apex, but ter- 



minating acutely ; so that the outline has more or 

 less the form of the blade of a sword. Sponge 

 unknown. X 130 linear. 



28. ENTIRELY SPINED. When the spines are equally 



dispersed over the spiculum from the base to the 

 apex. Halicfiondria incrustans, Johnston. X 

 260 linear, Pages 38, 40. 



29. B AS ALLY SPINED. When the spines do not occupy 



more than about one-third of the length at the 

 basal portion of the spiculum. Halicliondria In- 

 galli, Bowerbank. X 260 linear. 



30. MEDIALLY SPINED. When the spines occupy only 



about one-third of the length at the middle of the 

 spiculum. Halicliondria Ingalli, Bowerbank. X 

 260 linear, Page 38. 



31. APICALLY SPINED. When the spines occur only at 



and near the apex of the spiculum : from an unde- 

 scribed sponge, locality unknown. X 160 linear. 



32. TERMINALLY SPINED. When the spines occur near 



both the base and apex of the shaft of the spiculum 

 but not at the middle : from an un described species 

 of sponge, locality unknown. X 160 linear, Page 

 38. 



