Mr. J. Morris's Palatontological Notes. 87 



chalk, and therefore appear in the brownish and half-transparent 

 Belemnite as fine yellowish threads, which are still more marked 

 when it is wetted or oiled. M. Hagenow * describes two species 

 from the chalk of Rugen, and Quenstedtf has subsequently added 

 two more ; all the forms are found in the Belemnites of the En- 

 glish Chalk ; and it is somewhat remarkable that these parasitical 

 bodies have been hitherto only detected in the section, Belemni- 

 tella, D'Orb. — no traces of them having been observed in the 

 Belemnites of the Jurassic series. 



Talpina solitaria, Hag. PI. IV. fig. 6 a. 



Simple, slender, rarely branched, cylindrical or little com- 

 pressed channels, which either extend along the Belemnite in a 

 straight or little-curved direction, or follow its cylindrical form 

 in a spiral manner ; they are about the size of a fine knitting- 

 needle, and have only simple openings. 



Talpina ramosa, Hag. PI. IV. fig. 4. 



Very fine thread-like channels which are variously branched 

 or irregularly netted ; the orifices, which are visible to the naked 

 eye, always exist at the end of the tubes, as well as at those points 

 where the lateral channels diverge from the main one or from 

 each other. 



The specimen figured is from the chalk at Norwich, and kindly 

 lent me by Mr. S. Woodward. 



Talpina dendrina, Quenstedt. PI. IV. fig. 6 b, & 7. 



This form has a very dendritic appearance ; the branches are 

 compressed, closely aggregated, generally arising from a common 

 centre, and diverging in a somewhat radiating manner, variously 

 dichotomous and rarely anastomosing. 



This form is very common on the Belemnites from Gravesend 

 and Norwich, and has been figured with a view of directing the 

 attention of geologists to the subject, as it is doubtful whether it 

 has really arisen from organic action. 



Cliona or Clionites. Vioa, Nardo, Michelin. 



The origin of those singular organic impressions which occur 

 in the shells of Inocerami and the flinty nodules of the Chalk, long 

 remained in obscurity, but are now referred to the operations of 

 a sponge allied to or identical with Cliona. 



The excellent monograph by Mr. Hancock on the characters 



* Jahrbuch fiir Mineral. 1840, p. 671. t Die Cephalopoden, p. 4/0. 



