: CEPHALOPODA. 173 
Dosipicus, Stp. 1886. 
Somewhat like Ommastrephes. Lower portion of arms with 
large suckers, and the extremity with numerous small suckers, 
Tentacles with four or five hooks. 
Distribution, 1 species. Mediterranean. 
Famity LVY.—BELEMNITID. 
Shell consisting of a pen, terminating posteriorly in a cham- 
bered cone, sometimes invested with a fibrous guard. The air- 
cells of the phragmocone are connected by a siphuncle, close to 
the ventral side. 
BELEMNITES, Lamarck. 1801. 
Etymology, belemnon, a dart.* 
Example, B. puzosianus, Pl. IT., Fig. 5. 
Phragmocone horny, shghtly nacreous, with a minute globular 
nucleus at its apex; divided internally by numerous concave 
septa. Pen represented by two nacreous bands on the dorsal 
side of the. phragmocone, and produced beyond its rim, in the 
form of sword-shaped processes (Pl. II., Fig. 5).¢ Guard 
fibrous, often elongated and cylindiical; becoming very thin in 
front, where it invests the phragmocone.{ Suckers provided 
with horny hooks. 
More than 100 species of belemnites have been found in a 
fossil state, ranging from the lias to the chalk, and distributed 
oyer all Kurope. A few species have been found in the chalk 
* The termination ztes (from lithos, a stone) was formerly given to all fossi genera. 
; Five specimens were at one time in Dr. Mantell’s cabinet, and others are in the 
British Museum ; they were obtained by William Buy in the Oxford clay of Christian 
Malford, Wilts. <A still finer specimen, in Mr. Montefiore’s collection, was recently 
obtained from the lias of Dorsetshire by Mr. Day. The last chamber of a lias 
belemnite in the British Museum is 6 inches long, and 2} inches across at the smalle 
end; a fracture near the siphuncle shows the ink-bag. The phragmocone of a specimen 
corresponding to this in size measures 7} inches in length. 
t The specific gravity of the guard is identical with that of the shell of the recent 
_ pinna, and its structure is the same. Parkinson and others have supposed that it was 
originally a light and porous structure, like the cuttle bone; but the mucro of the 
sepiostaire, with which alone it is homologous, is quite as dense as the belemnite. We 
are indebted to Mr. Alex. Williams, M.R.C.S., for the following specific gravities o 
recent and fossil shells, compared with water as 1,000 :— 
Belemnites puzosianus, Oxford clay axon Hasshuiteen re ONCE 
Belemnitella mucronata, chalk ... .0. sso os ove 2077 
Pinna, recent, from the Mediterranean Ae woe, HO 
Trichites plottii, from the inferior oolite ... ... ... 2,670 
Conus monile, recent Seah Juke, ineeh Iuupsupes sh tessWicend mosoLO 
Conus ponderosus, Miocene, Touraine .., 4. .. «. 2,713 
