336 BULLETIN OF THE 
Mesodon Sayii, Binney, var. Chilhoweensis. 
An opportunity of examining the animal of this large form of JZ. Sayu, for 
which I am indebted to Dr. Lewis, shows that the genital system (Pl. IL. 
Fig. I) is similar to that of the typical form, excepting that the penis sac is 
still more developed, surpassing by three times the whole genital system in 
length. (See Terr. Moll. U.S., V., Pl. XI. Fig. 11.) 
The jaw and lingual dentition are the same as in the typical Say. I have 
figured on Pl. I. Fig. K, the dentition of this variety. 
Mesodon devia, Goutp. 
Freeport, Cowlitz Co., Washington Territory, Mr. Henry Hemphill. On 
Pl. II. Fig. G, I have figured the genital system of the typical form of this 
species: a@ is the penis sac ; }, the genital bladder and duct. 
Pomatia Humboldtiana, Vat. 
The individual examined was considerably smaller than Fig. 1, Pl. XI. of 
Mollusques Terr. et Fluv. du Mexique. It was collected by Dr. E. Palmer. 
The genital system is figured on Pl. II. Fig. J. The genital bladder (g. 6.) 
is small, on a long narrow duct ; the penis sac (p. s.) is long, tapering toa 
flagellate point, and receives the vas deferens (v. d.) about its middle ; there is 
a prostate gland (pr.) on a short peduncle, globular, with four accessory leaf- 
lets clinging to its base, giving a general rosette-like form to the gland. 
The jaw is short, arched, bluntly ending, with six broadly separated stout 
ribs denticulating either margin. 
The lingual membrane is long and narrow. Central teeth (Pl. II. Fig. 
K) pear-shaped, with no side cusps or cutting points ; laterals like the cen- 
trals, but asymmetrical ; marginals with one long inner bifid cutting point 
and one smaller side cutting point. 
Ochthephila tiarella, Wrens & Burra. 
Madeira, Dr. Hillebrand to Dr. Newcomb. The species is rarely found 
living. 
Jaw low, slightly arcuate, ends scarcely attenuated ; anterior surface with 
about 15 flat, broad, crowded ribs, scarcely denticulating the cutting margin. 
Lingual membrane with 21—1-21 teeth of same type as Plebecula lurida, q. V. 
Laterals about 9 on each side of the central. 
Ochthephila abjecta, Lowe. 
Madeira. Dr. Hillebrand to Dr. Newcomb. 
Jaw low, slightly arcuate, ends attenuated; cutting edge with a blunt 
median projection ; no anterior ribs. 
Lingual membrane with 24-1-24 teeth, of which about 4 on each side are 
laterals. Teeth of same type as those of Plebecula lurida, q. v. 
