Long. 0·36, long. spir. 0·26, lat. 0·12, div. 20°.

Hab. Monterey, Cooper. From shell washings.

The solitary specimen has the general aspect of O. granulosa on a very small scale.

Opalia retiporosa, Cpr. n. s. State Collection, No. 1014.

O. t. “O. bullatæ” formâ simulante, sed sculpturâ omnino diversâ; anfr. nucl. ?... (decollatis); norm. vii. subrotundatis, suturis impressis; costis radiantibus rotundatis, subarcuatis, haud varicosis, circ. xiv., super suturas tenue continuis; anfr. ult. seriebus nodulorum spiralibus irregularibus, vice costarum, instructâ, peripheriâ tuberculosâ; totâ superficie retiporosâ, interstitiis alte interpunctatis, punctulis minutissimis, confertissimis; basi vix costatâ, à serie nodulorum angulatâ; aperturâ rotundatâ; peritremati continuo, varicoso; labro haud sinuato; operculo? paucispirali.

Long. 0·28, long. spir. 0·20; lat. 0·10; div. 20°.

Hab. Catalina Island; 3 dead in 40 fm.; Cooper.

The texture has a rotten appearance; yet one of the specimens was stained with purple, and contained the dried remains of the animal, with its operculum. In the endeavor to extract this, the shell gave way.

Genus Nassa, Lam.