302 GASTROPODA. [Pectinibranchia. 



Fossil in the Post-Pliocene of Victoria. 



Remarks. T. W. Kirk mentions a T. zealandica from the Tertiary 

 beds near Petane, but in the very short diagnosis I fail to find any- 

 thing that would separate his species from T. australis. Many Kecent 

 specimens have the transverse strise passing only a short way up the 

 sides of the shell. 



Fam. SEPTID.E, Ball. 

 TritonidcB, Broderip. 



Animal having a short foot, broad and truncated anteriorly, tentacles 

 subulate, with the eyes at their outer sides or bases ; siphon short. 

 Jaw reticulated. Radula with the central tooth large, multi cuspidate ; 

 lateral tooth with a denticulated margin ; marginals falciform, pointed, 

 the inner ones usually with traces of denticulation. 



Shell solid, with an epidermis and continuous or irregularly dis- 

 posed varices ; protoconch smooth, paucispiral, subglobose, nucleus 

 not very prominent ; aperture oval, often excavated above by a deep 

 channel ; canal of variable length, not closed, and but rarely sinuate 

 at the base ; outer lip thickened exteriorly, denticulate inside, mostly 

 vertical ; columella generally plicated, twisted with the canal. Oper- 

 culum horny, with an apical or submarginal nucleus. 



The animals of this family are generally brilliantly coloured, and 

 they possess a purple gland secreting a coloured liquid. The period 

 of rest is marked upon the shell by a varix. 



KEY TO GENERA. 



A. Varices of shell not diametral i.e., directly opposed. 



a. Aperture without a channel at the suture. 



b. Canal short and truncated . . . . . . SEPTA. 



bb. Canal long and straight . . . . . . CYMATIUM. 



B. Varices diametral, no sutural channel . . . . ... AKGOBUCCINUJI. 



Genus 1. SEPTA, Perry, 1811. 



Septa, Perry, " Conchology, or the Natural History of Shells," 1811. Type : 

 Murex tritonis, L. Tritonium, Bolten, 1798, and authors ; not of 0. F. 

 Miiller, 1776. Triton, Montfort, 1810; not of Linne, 1768 (Crust.). 

 Eutritonium, Cossmann, 1904. 



Animal having the foot truncated in front, large and rounded 

 posteriorly ; tentacles long, cylindrical, eyes on tubercles at their 

 bases. Copulatory organ large, recurved. Central tooth of radula 

 short, transverse, with numerous denticles. 



Shell mostly large ; spire elongated, with angular whorls, ex- 

 cavated above ; protoconch lisse, subglobose ; last whorl gibbous, 

 with a strong axial varix, at about 120 from the labial varix ; base 

 convex, excavated around the canal ; aperture oval, contracted and 

 channelled above, narrowed below, and produced into a generally 



