OF CONCHOLOGY. 



15 



studded with somewhat distant, unequal, small hemispherical 

 papillae. Dorsal tentacles small, oblong ovate, slightly oblique, 

 on stout peduncles, coarsely and very obliquely laminated, and 

 retractile into tubular cavities. 



Branchial star small, one-third the width of the body, com- 

 posed of sixteen incurved lanceolate plumules, forming a beau- 

 tiful rosette around the vent. Mouth notched beneath ; no dis- 

 tinct head or labial tentacles. 



Genital papillae on the anterior third of the right side. Foot 

 oblong, much narrower than the mantle, truncately rounded in 

 front, rounded behind, and not projecting beyond the mantle 

 posteriorly. 



Color along the dorsal region wood brown, most minutely 

 punctured with white ; marginal region pale brownish grey, 

 papillae much darker. Dorsal tentacles and branchiae wood 

 brown, the former tipped with white ; peduncles colorless. 



Length, one inch. 



Habitat, Maiao Island. 



Genus CHROMODORIS, Alder and Hancock. 



I have remarked heretofore that the arrangement of colors on 

 Nudibranchia may be considered a generic character. The up- 

 per surface of the body and mantle of the species of this genus 

 are invariably lineated with bright colors and, with exceptions, 

 spotted. They excel those of any other genus in the gaudy, 

 variegated colors with which they adorn themselves, as the fol- 

 lowing species will prove. 



The nidamental ribbon is coiled up in two or three remote 

 whorls. While depositing it the animal remains motionless, or 

 nearly so, the body curved to one side. The coil is formed by 

 the foot, which folds up at its extremity, forming a groove, 

 through which the ribbon passes. The process is slow, occupy- 

 ing about two hours. 



Chromodoris variegata, Pease. Plate 7, fig. 1. 



Animal smooth, elongate, convexly rounded above. Mantle 

 narrow, sides nearly parallel. Anterior portion dilated and 

 rounded in front; posterior end rounded and slightly emargi- 

 nate. 



Branchial star as wide as the mantle, inserted far back ; plu- 

 mules ten, sub erect, lanceolate, pinnate, and retractile into a 

 common slightly tubular cavity. Vent prominent. 



Head furnished with short, stout, divergent, conical tentacles. 

 Dorsal tentacles large, clavate, erect, coarsely lamellate 



