PLEUROBRANCHUS. 
Species 5. (Copied.) 
PLEUROBRANCHUS PERFORATUS. Pie. testa ovatd, lata, 
pallidé ; apice anticé terminali; margine dor- 
sali supra arcuato, rotundato-quadrato ; 
gine inferiort subrotundo ; margine labiali recti- 
mar- 
usculo. 
THE PERFORATED PLEuROBRANCHUS. Shell ovate, wide, 
pale; apex terminal in front; dorsal margin 
arched, rounded above; lower margin rather 
rounded ; labial margin rather straight. 
Pariert. Enum. Moll. Siciliew, p. 87, pl. 21, f. 2. 
Hab. Mediterranean. 
This shell is larger in comparison with the rest of 
the body than any other species hitherto described. 
Species 6. (Copied.) 
PLeuropRaNcHUS Paraconicus. Ple. testa oblonga, 
pallidé fulvad, angustd, subquadratd, concentricé 
tenuiter lirata; spird productdé, ad dorsum ter- 
minali ; margine superiori subdeclivi, ad terminum 
rotundo ; margine labiali recto; margine inferiort 
obtusé subquadrato ; margine dorsali recto. 
Tue ParaGontan PLeuroprancuus. Shell oblong, pale 
fawn, narrow, subquadrate, concentrically finely 
ridged; spine produced, terminal at the back; 
labial margin straight; lower margin obtusely 
subquadrate ; dorsal margin straight. 
D’Orsieny. Voy. Amér. Mérid., pl. 17, f. 4, 5. 
Hab. Patagonia. 


Species 7. (Copied.) 
PLEUROBRANCHUS cITRINUS. Ple. testd oblonga, sub- 
angustata, laevigata, compressd, subaurantia ; 
apice ad dorsum terminali; margine superiori 
supra apicem elevato ; margine labiali rectiusculo ; 
margine inferiort quadrato ; margine dorsali recto. 
cirron PLeuroprancuus. Shell oblong, rather 
narrow, smooth; apex terminal at the back, com- 
pressed, slightly orange-tinted; apex terminal at 
the back; upper margin raised above the apex; 
labial margin rather straight; lower margin quad- 
rate; dorsal margin straight. 
Ripper. Voy. Afric., p. 18, pl. 5, f. 2. 
Hab, Africa. 
It may be supposed from the figure given of this 
species in Riippel’s work that the upper margin of the 
outer lip is higher than the spine. 
THE 

Species 8. (Copied.) 
PLEUROBRANCHUS BREVIFRONS. Ple. testd oblonga, sub- 
quadratd, levigata ; spiré ad dorsum terminali ; 
margine superiori recto, brevi ; labio externo supra 
contracto, infra subexpanso; margine inferiori 
rotundato ; margine dorsali rectizsculo. 
THE SHORT LEAF PLEvuROBRANCHUS. Shell oblong, 
rather square, smooth; spine terminal at the 
back; upper margin straight, short; outer lip 
contracted above, a little expanded below; lower 
margin rounded; dorsal margin rather straight. 
Puiiri. Enum. Moll. Sicilie, p. 87, pl. 20, f. 5. 
Hab. Mediterranean, 

