166 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 58. 



SYNCERA COMPACTA (Carpenter). 



Plate 12, fig. 4. 



1864. ? Hiidrobia compacta, Carpenter, Rept. Brit. Ass. Adv. Sci., 1863, 



p. 618. 

 1SG4. ? Hydrobia compacta, Carpenter, Ann. Mag. Nat. Hist., ser. 3. vol. 13, 



p. 478. 



Shell very minute, globular (probably chestnut brown). Nuclear 

 whorls not differentiated from the remaining turns. Postnuclear 

 whorls feebly shouldered at the summit, inflated, and strongly 

 rounded, marked by decidedly retractively slanting axial lines of 

 growth. Suture strongl}'^ impressed. Periphery of the last whorl 

 inflated, well rounded. Base short, strongly rounded. Aperture 

 large, subcircular; outer lip thin; inner lip strongly curved, passing 

 into the strong parietal callus, which is reflected over the base. 



The type, Cat. No. 16209, U.S.N.M., was collected at Cape St. 

 Lucas, Lower California. It has four whorls and measures — alti- 

 tude, 1 mm. ; diameter, 0.75 mm. Doctor Carpenter's type, the only 

 specimen at hand, is a dead, worn shell, which I strongly suspect of 

 being a young specimen. It is undoubtedly closely related to Syncera 

 trarislucens. 



Genus BARLEEIA Clark. 



The genus Barleeia was described by William Clark in 1855 % who 

 gives an interesting account of the animal of Barleem rubra Montagu, 

 the hologenotype of the proposed genus, which, considering the 

 scarcity of anatomic data, bears repeating here : 



Shell. — The color is plain red-brown, smooth or slightly wrinkled, of 4i to 

 5i tumid volutions, which form a rapidly increasing cone. Aperture oval, 

 entire, contracted above, rounded basally; outer margin sharp, without the cal- 

 lous pad of the Rissoa. Axis one-tenth, diameter one-seventeenth of an inch. 



Animal. — The mantle is plain, even with the margin of the shell, and without 

 the filament seen at the upper angle of the aperture in many of the Rissoa. 

 Rostrum very short, not corrugated nor capable of much extension, brindled 

 above with dark smoke-colored, fine, irregular, close-set lines, below pale yel- 

 low ; buccal disk of the same color, of small area, crosially and vertically 

 cloven, containing the usual masticatory processes of the Littorinidae; neck 

 dark, but not so much so as the rostrum, quite plain and without appendages. 

 Tentacula very short, strong, broad, not in the least setaceous, with perfectly 

 rounded, somewhat spatulate extremities ; they are not vibrated on the march ; 

 color very pale yellowish-white, with a line of sulphur-colored beads or minute 

 flakes running centrally from base to point ; eyes very large, black, fixed on 

 bright sulphur inflations at the external bases. Foot an elongated, rather 

 narrow oval, anteally arcuated, labiated, with scarcely perceptible auricular 

 points, posteally rounded, emarginate in the centre of its termination ; color, 

 in the middle of the upper part, confused flake-white, margined with a belt of 

 pale smoke hue; sole pale yellow with a decided depressed longitudinal line 

 on the center of the posterior half, not constricted under the slight auricules 



> British Marine Testaceous Mollusca, pp. 392-395. 



