12 MARINE POLYZOA. 



not only of the vittae, but on the surface of the cell itself. The 

 central umbo or crest posteriorly is a marked feature. 



15. CATENICELLA GIBBOSA. PL VII. figs. 3, 4. 



Cells pyriform, ventricose posteriorly, mnch attenuated down- 

 wards. Avicularia small, placed in front close to the side of the 

 aperture, at the base of strong conical pointed processes which 

 project in front, and are connected across the top of the cell by 

 a prominent toothed ridge. Vittse long, linear, entirely lateral. 

 Surface in front with a few scattered acuminate papillae. 

 Catenicella gibbosa, Busk, Voy. of Rattlesn. i. 360. 

 Hab. Prince of Wales Channel, Torres 3 Strait, 9 fathoms, mud. 



Of a dark lead colour when dry. Forms an elegantly-branched 

 bush, about 2 inches high. The gibbous form of the cells, and 

 the peculiar anterior position of the avicularia, at the base of the 

 projecting lateral processes, at once distinguish it from all the 

 other vittate species. The toothed (sometimes entire) ridge ex- 

 tending between the two lateral processes across the top of the 

 cell and overlapping the mouth like a penthouse, is also a very 

 peculiar feature. 



16. CATENICELLA TAURINA, n. sp. PL XI. 



Cells oval or subglobose. Avicularia large and strong, fre- 

 quently transformed into long and large ascending (not retroee- 

 dent) spines. Surface of cell smooth. Vittse small, inconspicuous, 

 lateral. Surface in front smooth. Ovicelligerous cells gemmate. 



Hab. Algoa Bay, &c., South Africa. 



This species is at once distinguishable by the peculiarity in the 

 conformation of the ovicelligerous cells, and the spines, which are 

 as long as in C. cornuta, are not retrocedent as in that species, 

 but ascend directly. The habit of the polyzoary is also very pe- 

 culiar, growing in long branching tufts, and the smaller branchlets 

 composed of the cells arise in pretty regular whorls around the 

 central stems ; giving to the whole somewhat of the aspect of 

 Thuiaria thuja. 



y. Simplices. Without vittce or fenestrae. 

 Catenicellse simplices, Busk, Voy. of Rattlesn. i. 363. 



17. CATENICELLA CARINATA. PL VI. figs. 4, 5, 6. 



Cells oval, narrowed at each end 5 lateral processes (without 

 avicularia ?) projecting horizontally outwards from the side of the 

 aperture, which is nearly central. Mouth with a small tooth on 

 each side, and below it a triangular space with three strong coni- 



