C 803 ] 
XCVII. A DiJJertation on the Belemnites, in 
a Letter to Smart Lethieullier, Efquire } 
F 1 R. S. by Mr . Guftavus Brander, 
F. R . S. 
S I R, 
Read Nov. 2 i.ttt j s owing to the pleafure of fome 
754* j ate converfations with you, upon the 
fubjedt of natural hiftory in general (in which I am 
always fure to profit), that I now take the liberty to 
offer you my fentiments concerning the belemnitps. 
The belemnites is a foflil, that has hitherto per- 
plex’d the naturalifts of all countries : it has been 
treated of by various authors, and in turn been 
afcribed to all the three kingdoms of nature 5 but, 
apprehending the road to truth ftill open, I am en- 
couraged to refume the fubjedt once more, and beg 
leave to deliver it as my opinion, that it belongs to 
the teftaceous part of the animal kingdom, and to 
the family of the nautili. The nautilus, or failor, is 
a concamerated fhell, with a fyphunculus running 
through every cell, fee 'Tab. XXXIV. Fig. 1 . The 
fyphunculus, and the concamerations, are the generi- 
cal charadter of this tribe, and are fuppofed to ferve 
the animal to buoy up its fhell, by which means it 
can fwim or fink at pleafure. 
Thofe that are curv’d are very common both in 
the recent and foflil Hate : the ftrait ones have hi- 
therto only been met with foflil, and are common 
enough in Sweden, Livonia, and feverai parts of 
Germany ; and have, by naturalifts, been called or- 
y I 2 thoceratitae ; 
