102 



to Cape Mendocino ; often met with in Bay of 

 San Francisco. 



Gents Mexipea. (Lamx.) 



Menipea occiclentalis. Trask. Plate 4, fig. 4. 

 — Polypidom tufted, alternately branched, cal- 

 careous, from one to two inches high, color white 

 and yellowish ; branchlets rise from the superior 

 and lateral portions of the internodes. Cells 

 much compressed, diminishing rapidly from 

 above downward ; three on each internode. — 

 Apertures roundly oval, with a slightly raised, 

 rounded rim, which is armed with two stout, 

 rounded, curved and acute spines, pointing up- 

 ward and inward, one always being more or less 

 sub-central. Internodes sub-triangular, with a 

 somewhat tortuous, rounded rib passing through 

 the centre, the lateral and superior angles sur- 

 mounted by two or three long, rounded, irregu- 

 lar spines ; points dark colored. The upper nodes 

 are armed with four long and irregular spines, 

 the two central being much the longest. All 

 the spines more or less acute. 



Prom Cape Flattery (Oregon) to Santa Barba- 

 ry. Frequent among rejectamenta, Bay San 

 Francisco. 



Genus Screpocellaria. (Van Bexeden.) 



Scrupoceliaria Californica. Trask. Plate 4, 

 ffg. 2. — Polypidom confervoid, jointed, growing 

 in bushy tuits, calcareous ; cells biserial, alter- 

 nate, from seven to nine on each point, facing 

 somewhat obliquely outward ; apertures roundly 

 oval, margins incrassate, and sustaining a single 

 spine, which rises from the rim of the aperture 

 on its upper and outer edge from the base of the 

 inner edge ; a pedunculate, pear-shaped opercu- 

 lum covers a portion of the aperture. The vi- 

 bracular and avicularian organs are wanting. — 

 The lateral cup-like cells sustain two round, ob- 

 liquely set spines rising from the posterior edge. 

 The affinities of this species are with that of S. 

 macandrei. 



Bay San Francisco. 



Gexums HippoTnoA. (Lainx.) 



Hippothoa amabilis. Trask. Plate 4, fig. 5. 

 — Polypidom creeping, branched irregularly, cal- 

 careous, polished, branches anastomosing ; aper- 

 tures large, oval, with a rounded, thickened rim ; 

 within the upper part of the aperture a shining 

 calcareous hemispherical operculum ; the anas- 

 tomosing branches are given off, for the most 

 part, opposite the aperture, but this cannot be 

 said to be a strict rule as regards this species. 



Found on stones within half tides in the Bay 

 of San Francisco. 



Mr. Garratt"s paper on new species of marine 

 shells of the Sandwich Islands. 



Murex-exigua. Garrett. 



Shell, oblong-oval, solid, scabrous, and whi- 

 tish ; whorls about six, somewhat emgulated 

 above, coarsely furrowed spirally, and crossed by 

 numerous varices, which are crenulated by the 

 spiral furrows ; base furnished with a short, sub- 

 closed, slightly oblique canal ; aperture round- 

 oval ; outer lip crenulated. 



Length five lines. 



Habitat : Pure, shallow pools on the rocky 

 coasts of Hawaii. 



PvEPfRA-STitiATELLA. Garrett. 



Shell, ovate, solid, smoothish, ventricose above, 

 blackish, with sub-equidistant, spiral, pale lines ; 

 spire short, conic, convex ; aperture large, 

 elongated, notched above, and faintly lineated 

 within ; outer Up dilated, slightly, toothed 

 within, and minutely crenulated on the edge, 

 where it is margined with purple ; columellar 

 lip depressed, spreading, smooth and toothed 

 above ; throat bluish. 



Length seven lines. 



Habitat : Hawaii. 



Observations. — This species is not common at 

 the above locality ; they are generally found at- 

 tached to the spines of the Echinus -atratus (Li?i) 

 in the cireumlitteral zone. 



Tlrbo-multieixeata. Garrett. 



Shell, solid, sub-globose, sub-perforated ; spire 

 consisting of about three volutions and slightly 

 depressed ; the whole surface marked with nu- 

 merous, spiral, coarse, equidistant, elevated, 

 reddish lines ; in a pale ground. 



Length less than a line. 



Habitat : Hilo Bay, Hawaii. 



In the cireumlitteral zone. 



Trociius-steevtula. Garrett. 

 Sub- genus. 

 Margarita. 

 Shell, thin, depressed, somewhat pellucid, 

 glossy ; surface marked with crowded, fine, reg- 

 ular, revolving strioe ; body whorl large ; spire 

 small, with four volutions, separated by an ob- 

 solete sutural line ; base somewhat flattened, 

 and umbilicated ; columella slightly reflected 

 over the umbilicus ; color, variously mottled 

 and striped with pale fulvous, greenish and 

 pink on a pearly ground. 



Length one line ; diameter the same. 

 Habitat : Lairninarian zone, Hawaii. 



Peeukotoma-reticulata. Garrett. 

 Sub-genus. 

 Mangelia. 



Shell, solid, sub-fusiform, turreted, whitish, 

 with a pale purplish spiral zone ; whorls six or 

 seven, convex, and marked with numerous, reg- 

 ular, series of equidistant spiral rows of squarish 

 punctures which give the surface a beautiful 

 reticulated appearance ; suture crenulated; base 

 somewhat wrinkled and provided with a short, 

 slightly oblique canal ; aperture elongate, nar- 

 row and slightly contracted by the outer lip ; 

 labrum thickened outside and in, crenulated or 

 toothed and deeply notched above ; columella 

 callosed. 



Length three lines. 



Habitat : Hilo Bay, Hawaii. 



Rissoa-crassiladrum. Garrett. 



Shell, solid, acute, turrito-conical, smooth, 

 glabrous, white or a very pale fawn color ; whorls 

 eight, plano-convex ; sutural line faintly im- 

 pressed ; aperture ovate ; labrum somewhat di- 

 lated, very mnch thickened and dentatcd in the 

 inner margin ; columellar lip broadly callosed. 



Length four lines. 



Habitat : Rocky coast of Hilo, under stones, 

 in the cireumlitteral zone. 



