88 Mr. J. Morrises Palaontological Notes. 



and habits of the recent species, in a late Number of the ' An- 

 nals/ is well known. 



Fossil species have been noticed in the shells of the Crag, Lon- 

 don clay, the Chalk, and the Gryphsea of the Lower Greensand ; 

 and Prof. M'Coy has lately described a species under the name of 

 Vioa prisca, in an Avicula from the Silurian rocks. 



Mr. Parkinson (1811) appears to have first noticed these bo- 

 dies as occurring in the state of siliceous casts, and suggested 

 that they may have been the work of some animals of a nature 

 similar to the Polypes ; and subsequently in 1814 the Rev. W. 

 Conybeare * pubhshed a memoir on them, with some excellent 

 illustrations of the common species, and asserting " that the ori- 

 gin of these bodies was widely different from that assigned by 

 Parkinson, they being in fact siliceous casts moulded in little 

 hollow cells excavated in the substance of certain marine shells ; 

 the work perhaps of animalcules preying on those shells and on 

 the vermes inhabiting them." At the end of this paper is an 

 interesting letter from Dr. Buckland which has been generally 

 overlooked, as showing at that early period his suggestion that 

 similar organisms which committed the ravages in the recent 

 oyster, probably also effected the perforations in the shells of the 

 extinct Inocerami : — 



" The hollows that afforded a mould for the formation of these 

 singular bodies appear to me to have been the work of some mi- 

 nute parasitical insect. The small aperture, the cast of which 

 now forms the projecting axis of each globule, was probably per- 

 forated by this intruder as the entrance to his future habitation ; 

 having completed this passage, and excavated at its termination 

 a cell suited to his shape and convenience, he appears by the aid 

 of a delicate auger or proboscis to have drilled many minute and 

 almost capillary perforations into the substance of the shell ou 

 every side around him, taking care to leave always partitions suffi- 

 cient to support the roof of his apartment. Having exhausted 

 all the nourishment which could in this manner be procured with 

 safety from the vicinity of this first establishment, the insect 

 appears to have emigrated, and after working for itself a lateral 

 passage to a sufficient distance, to have formed a new settlement 

 in the midst of fresh supplies. In the recent oyster shell which 

 I have transmitted, you will perceive that this process has been 

 carried on, to a great extent, in the intermedial matter between 

 two or three sets of the pearly plates comprising it; and yet 

 without effecting the destruction of the exterior crust, or in any 

 degree injuring the inner surface of the shell, which remains un- 



* " On tK". origin of a remarkable class of organic impressions occurring 

 in nodules of flmt " (Geol. Trans. 1 ser. vol. ii. p. 328. pi. 14). 



