112 MURICIDA. 
ment of the adult character. The young Purpura shells retain 
the embryonic Sinusigera at the summit of the spire for a con- 
siderable period, but it is eventually lost by erosion. That all 
the species which have been referred to Sinusigera are larval 
forms of various species of Purpura does not follow, from this 
observation; some of the related genera may be involved. Mr. 
Arthur Adams has identified another species of Sinusigera with 
Purpura biserialis, and Mr. Craven thinks that his S. perversa 
is the young of a Triforis or of some allied genus in Cerithiide. 
Sinusigera is pelagic, and is encountered in mid-ocean, in 
tropical seas having feeble currents and where calms prevail. 
Mr. Craven, who has recently monographed the genus, enu- 
merates twenty species. | 
PurpurorDEA, Lycett. 
Distr.—P. nodulata, Lycett (xliv, 24). Oolite, England. 
Shell turriculated, ventricose; summit of the spire sharp; 
whorls convex, with a line of spines or tubercles on the shoulder ; 
columella smooth, rounded, excavated in front; siphonal notch 
wide, no groove at the posterior junction of lip and columella ; 
outer lip thin. Fossil. 
This fossil genus has been confounded with Purpurina, d’Orb.: 
its typical forms appear to be close to Purpura, and the species 
I figure has some resemblance to the recent P. chocolatum ; 
whereas Purpurina is nearly related, apparently, to Cancellaria. 
The distinctive character from Purpura consists in the close 
junction of lip and columella posteriorly. 
Lysis, Gabb. 
Distr.—L. duplicosta, Gabb (xliv, 25,26). Cretaceous, Cali- 
fornia. 
Stomatiform, very oblique; spire moderate ; whorls costate ; 
aperture narrow, outer lip simple, inner lip straight, concavely 
expanded over the wide umbilicus so as to completely cover it. 
Supposed by Gabb to be nearly related to Stomatia; I have 
examined authentic specimens, and do not hesitate to refer it to 
the Purpure. 
Jopas, H. and A. Adams. 
Distr.—I. sertum, Brug. (xlv, 40). Polynesia. 
Shell ovate, rugose, last whorl large; spire acuminate; aper- 
ture moderate, emarginate and channeled in front; columellar 
lip covered with a thin enamel, and with a prominent plait-like 
callosity at the hind-part ; outer lip sinuous, crenate within. 
VEXILLA, Swainson. 
Distr.—4 sp. Japan, Philippines, Polynesia, V. vexilium, 
Chemn. (xliv, 27). ae 
