208 Canon A. M. Norman on 



Genus Terebripora, d'OrLigny. 



This interesting g-enus, the exact, position of which cannot 

 be determined until tlie animal shall have been examined, 

 but which is presumed to be a burrowing Polyzoon, was 

 instituted by d'Orbigny in 1841 * to include two species, 

 Terebripora ramosa and T. irregularis^ which he had found 

 in shells of Calyptraia, Crepidida, and Pecten off the South- 

 American coast. 



In 1865 Paul Fischer published an excellent paper on the 

 family t, in which he enumerates all the species both recent and 

 fossil presumed to be referable to his '' Famille des T(^rdbri- 

 porides." In this paper eight recent and fourteen fossil species 

 are recorded. Two of the recent species had been found in 

 European seas — one, Terebripora Orbigniana, Fischer, bur- 

 rowing in shells of Ostrea edulis at Arcachon, and in Conus 

 mediterraneus and Triton nodifer in the Mediterranean ; the 

 other, Spathipora sertumj Fischer, found at La Rochelle, 

 Arcachon, and the Mediterranean in shells of Lutraria ellip- 

 tica, Cardium norv( gicurn, Pectunculus gJycimeris, and Triton 

 nodifer. In 1880 M. J. JuUien \ added another recent 

 species, T. Fischeri, which was found in a shell of Buccinum 

 from Cape Verd Islands. 



Terebripora ditrupoey sp. n. (PI. IX. figs. 4-7.) 



Terebripora has a mode of growth analogous to that of 

 Ilippothoa divaricata, but instead of running over the surface 

 of shells &c. as in the latter species, the whole polyzoary is 

 buried in its substance, except that the orifices of the zooecia 

 open through the surface. The thread-like connecting fibres 

 or stolons in all species hitherto described appear to be quite 

 simple, but in T. ditrupce they consist of lines interrupted on 

 one side by small lateral projecting processes (fig. 5). The 

 zooecia are not in the same plane as the connecting fibre, but 

 at right angles to it, in such a manner that they are also 

 perpendicular to the surface (fig. 6). Owing to this position 

 of the zooecia their lower portion is too deeply seated to be 

 seen with the microscope; the oral opening has a somewhat 



* d'Orbigny (A.), * Voyage dans TAm^rique m^ridionale,' vol. vi. p. 23, 

 pi. X. 



t Fischer (P.), " £tude sur les Bryozoaires perforant de la Famille des 

 T6rebriporides," Nouv. Arch, du Museum, vol. ii. pp. 293- (J13, pi. xi. 



X JuUien (J.), " Desc. nouv. Espece de Bryozoaire perforant du genre 

 Terebripora, d'Orbigny," Bull. Soc. Zool. de France, lb80, pp. 1-4 and 

 woodcut (separate copy). 



