592 
ON A SPECIES OF THE GENUS MITRA. 
PROCEEDINGS OF LEARNED SOCIE- 
TIES. 
ZOOLOGICAL SOCIETY 1836. 
Specimens were exhibited of numerous 
Shells of the genus Mitra, Lam., and of one 
species of Conoelix, Swains., forming part of 
the collection of Mr. Cuming ; and an ac- 
count of them by Mr. Brouerip was redd, 
commencing as follows ; 
•• The species of the genus Mitra, Lam., 
which I am about to describe, had been sent 
by Mr. Cuming, in whose cabinet they are, 
to Mr. Swainson, whose intimate acquaint- 
ance with this family renders him so particu- 
larly competent to the task of describing them. 
I'hey weie named by him, and he also made 
notes respecting them before returning them. 
In the following account of them 1 have 
retained Mr. Swainson’s name in every in- 
stance but one : and whenever he has made 
any written obseivations 1 have quoted ihem. 
Characters, habitats, ike. of the following 
species were then given, and are printed in 
the “ Proceedings.” 
Genus Mitra (Lam. and Swains.). Mitra 
fic6w(osa( representing MMbiZa, Type 5, 1, Sw.;, 
{Supainsomi (Type 1 , i.), Ahcillides (5,(2?L 
mawra (representing Tiara Joraminutu, Tyie 
(1. 4.),Julvei>cens (5, 1.), testacea (5, 1. repre- 
senting /M/i7aJ,/Mtoa var. (I, 2. representing 
Tiarai, chrysostoma (5, ). representing/er- 
ruginea), ti-istis (2,4.), ‘eind ejf'usa fl, 5.). 
Genus 1 iara, Sivains. (Miira, Lam.) T'iara 
foraminata (representing Mitra maura, 1 ype 
2, 4 ), luuricuta, mucronuta, catenata (1,3.), 
multicostuta, rosea niillecostaia (the 
close-set longitudinal ribs and cancel ated 
base give this shell, which may not have at- 
tained its full growth, the aspect of a Can- 
cellaria), lineata (5, 1), nivea (5, 3.), au- 
rantia, tereOralis, crenaia (5,3, or 3, 3.), rubra 
(1, 2 ), semiplicata, and attenuata (5, 1 )• 
Mr. Swainson had wiitten on the pa; er 
containing Tiura terebralis, " '1 ype 4,4. This 
is one of tiie most extraordinary shells in the 
collection, as it so closely resembles the Mitra 
Terebralis that, but for its possessing the 
generic characters of Tiar t , it might pass for 
the same species. 
It IS one of the most slender of its genus, 
and has very much of the general character 
and form of a Terebra ; and its resemblance 
to Terebra is increased by the circumstance 
of its having one spiral groove, more deeply 
impressed than the others, placed at about 
one third of the length of each volution be- 
fore the suture. The points of contact of the 
decussating with the longitudinal grooves 
are deeply impressed, 
There is a fine specimen in Mr. Broderip’s 
collection. 
Mr. Sowerby has furnished me with the 
account of this species. 
Genus Conoelix {Sioains.). Conoelix Virgo 
(representing Conus Virgo). 
The following observations by Mr, Swain- 
son elucidate his notes in relation to the 
Mitres, appended to most of the characters of 
the shells above named : 
“ I'o render my explanation of the notes 
and references attached to the different 
species of the Mitrance more intelligible to 
conchologists, it wdll be necessary for me to 
state, in as few words as possible, the result 
of my investigation of this subfamily, and the 
principles which have regulated these numeri- 
cal indications. 
” I have already, in another work, charac- 
terized the family Volutidee.. which appears to 
be that primary division of the Carnivorous 
Gasteropoda {Zoophaga, Lam.), which i-epre- 
sents the Rasorial type among Birds, the 
Ungulata among Quadrupeds, and the Thus a- 
nura among perfect Insects (Ptilota) : these 
analogies being of course remote, although 
founded on the structure of the animal, no 
less than on its testaceous covering. It thus 
follows that the Lamarckian Mitrce, instead of 
a genus, constitute a subfamily, w^hich ap- 
pears to be the subtypical group of the circle. 
The five genera composing this circle I have 
long ago characterized ; and here, for some 
years, my analysis of the group terminated. 
The inspection, however, of the numerous 
species brought home by Mr. Cuming, and 
the gradually augmented number in my owm 
cabinet, seemed to invite a still further and 
more minute investigation, for the purpose 
of ascertaining if any, and what, subgenera 
were contained in the more crowded groups 
of Mitra 'And Tiara. This investigation was 
carried on, at intervals, for nearly twelve 
months ; and the result surpassed my most 
sanguine expectations. It has convinced 
me that not only does each of the genera of 
the Mitrance represent analogically the corres- 
ponding groups of the Volutince, but that 
the same relations can be demonstrated 
between the minor divisions of the genera 
Tiara and those of Mitra : in other words’ 
that these latter represent all the subfamilies 
and genera of the other Volutidee, while they 
preserve their own peculiar or generic 
character. What I have just said on the 
parallel relations of analogy between the 
Mitrance and the Volutidee, is strictly appli- 
cable, in fact, to the genera Mitra and Tiara, 
the [irimary divisions of each of which can 
thus be demonstrated subgenera. Nor is 
this all : the materials I have been for so 
many years collecting have enabled me to 
ascertain, in very many instances, that the 
variation of the species, in each of these 
subgenera, is regulated on precisely the same 
principle. Hence it follows that the two 
circles of Mitra and Tiara, like the two 
divisions of Mr. MacLeay’s Petalocera, 
contain species representing each other, so 
that if their generic character is not attended 
to, it is almost impossible to discriminate 
them even as species. Many instances of 
this extraordinary analogy might be men- 
tioned, independent of that here alluded to, 
between Mitra Terebralis and Tiara Terebralis, 
“ Selecting this shell to illustrate the 
numbers “ Type 4, 4,” I may observe, that 
‘ Type 4’ signifies that it belongs to the 
