FRONTAL SPINE OF HYBODUS.— MUS MESSORIUS. 605 



growing on a dead shell,"— -for the root of the Ventriculite is 

 not at the smaller extremity, 

 but at the larger. Flints of 

 this shape are very common ; 

 the marking * shows the sec- 

 tion of the stem of the enclosed 

 zoophyte, the openings, o, are 

 the hollows left by the radicle- 

 processes. I fear you will 

 scarcely understand my mean- 

 ing from this hurried scrawl ; I 

 but I have so little leisure at 

 my command, that I am com- 

 pelled to write in great haste. ° 

 — G. A- Mantell. — Crescent Lodge, Clapham Common. 



[Our best thanks are due to Dr. Mantell for kindly correcting an error 

 into which we had fallen in our remarks on the Ventriculite, a tribe of fos- 

 sils to which, as it is well known, he has most successfully given his atten- 

 tion.— Ed.] 



Extract of a Letter from Miss Anning, referring to the 

 supposed frontal spine in the genus Hybodus. — " In reply to 

 your request I beg to say that the hooked tooth is by no means 

 new ; I believe that M. De la Beche described it fifteen years 

 since in the Geological Transactions, I am not positive ; but 

 I know that I then discovered a specimen, with about a hun- 

 dred palatal teeth, and four of the hooked teeth, as I have 

 since done several times with different specimens. I had a 

 conversation with Agassiz on this subject ; his remark was 

 that they were the teeth by which the fish seized its prey, — 

 milling it afterwards with its palatal teeth. I am only sur- 

 prised that he has not mentioned it in his work. We gene- 

 rally find the Ichthyodorulites with them, as well as cartila- 

 ginous bones." — Mary Anning. — Lyme Regis, April 7, 1839. 



[As Miss Anning speaks of 100 palatal teeth, she probably refers to 

 the genus Acrodus, which may very possibly be furnished with an organ 

 similar to the one possessed by Hybodus, as the genera are closely allied. 

 Mr. De la Beche makes no allusion to its existence in the Geological 

 Transactions. — Ed.] 



On the disappearance of the Mus messorius, Shaw, (Har- 

 vest mouse); followed by a notice of Mus sylvaticus, Linn. 

 (Field or Wood mouse). — These beautiful little red mice 

 {Mus messorius) were three or four years ago very abundant, 

 as I used to cause a notice to be given me when a rick in the 

 neighbourhood was to be taken into the barn, as they take 

 refuge in the lowest part of the rick, burrowing in the ground 

 underneath ; and I have seen scores of the little tame crea- 



Vol. III.^No. 36. n. s. 3 x 



