FAMILY 8. CANALIFERA. 195 
Pl. CCXL. Fig. 10 and 11. 
Murex PINNULIFERUS, Nobis. 
Typhis pinnatus, Broderip, Proceedings Zool. Soc., 1832, p. 178. 
RANELLA, Lamarck. 
Testa ovata, vel oblonga, depressiuscula, varicibus plurimis, plus minusve 
obliquis, continuis, in seriem longitudinalem utroque latere dispo- 
sitis ; columella arcuata, rarO umbilicata, sepé lamina tenuissima, 
subrugosa, obtecta, in canalem brevissimum, subrecurvum, desi- 
nente ; apertura subovata, labro crenulato, superné canaliculato. 
Operculum corneum. 
The formation of this genus is one of the more recent improvements 
which Lamarck effected in his subdivision of the Linnean Murices. De 
Montford, however, is entitled to the credit of having first suggested 
it; he proposed to separate the Ranellz from the Murices under the new 
generic title of Buffo, and he afterwards created another genus, Apollon, 
for the sake of distinguishing the few that are umbilicated. It is in the 
singular disposition of the varices that these mollusks exhibit their generic 
peculiarity ; instead of being developed in frequent succession, as in the 
Murices, one varix only is deposited on the completion of every half volu- 
tion ; they thus become arranged in such a manner as to form a longitu- 
dinal shelf, as it were, down each side of the shell. The Tritones, on the 
other hand, only deposit a varix occasionally, and at longer intervals. 
The shell of Ranella may be described as being ovate, or oblong, and 
rather depressed, with a number of varices, which are more or less oblique, 
continuous, and deposited in two longitudinal series, one on each side ; 
the columella, which is curved, rarely umbilicated, and often overspread 
with a thin layer of testaceous matter, ends in a very short, somewhat 
recurved canal; the aperture is nearly ovate, the lip is crenulated, and 
at the upper part it is canaliculated. 
2c2 
