266 POLYZOA INFUNDIBULATA. 



their base the cells are a little narrowed and inclined to be horizon- 

 tal, but the upper portion is more or less raised, and, in some species, 

 becomes quite erect : they are arranged normally in rows which 

 radiate from a centre, but this disposition is often interfered with, 

 when the cells become confluent, as they often do in the progress of 

 development. 



The polypidoms are always small, neat, and pretty. They are 

 found on submarine bodies affixed by a thin calcareous basis, the 

 form of which varies in different genera ; and the cells are produced 

 from its free or upper surface. These are developed in regulated 

 succession by buds proceeding from the base of the primary ones, 

 and the bud must apparently always be projected from the exterior 

 side of the parent cell, for otherwise it would not be easy to explain 

 the fact of their never covering up the central cells, and of their 

 being set in rows or series which diverge from a centre or a medial 

 line. The form of the polypidom is liable to be influenced by the 

 nature of the site on which it is developed, and this has given rise 

 to some difficulty in the determination of the species. They have 

 probably been over multiplied, but this seems unavoidable in the 

 present state of our knowledge of them. 



The ova are unknown. The polype never produces an external 

 ovarian capsule. 



1. TUBULIPORA,* Lamarck. 



CHARACTER. Polypidom depressed, circular or lobed, adhe- 

 rent by a thin calcareous basis : cells clustered, inclined to be 

 rowed, erect or subhorizontal, more or less free at the round 

 terminal aperture. 



* With a thin sessile cupped basis. (Discopora, Fleming.) 



1. T. PATINA, base sessile, circular and cupped, with a thin 

 scored margin ; the tubular cells crowded towards the circum- 

 ference and rowed, with a plain circular aperture. Pallas. 



PLATE XLVII. FIG. 1, 2, 3. 



Caryophyllus sive Fungites minimus tubulosus littoris Ariminensis, Plane, de Conch, 

 min. not. 26. tab. 2, no. 9. Madrepora verrucaria, Lin. Syst. edit, x, 793. Lin. 

 Syst. 1272. Pall. Zooph. var. ft. 281. Turt. Gmel. iv, 616. Oliv. Zool. Adriat. 

 218. Esper Madrep. tab. 17, fig. a. A. (not good.) Turt. Brit. Faun. 204. 

 Stew. Elem. ii, 426. Hogg's Stock. 38. Millepora verrucaria, Ellis and Soland. 

 Zooph. 137. Tubulipora patina, Lam. Anim. s. Vert, ii, 163 : 2de edit, ii, 244. 

 Rifso TEurop. Merid. v, 338. Blainv. Actinolog. 425. Johnston in Trans. 



* From lubulus, a tube ; and xoos a passage. 



