DOKis. 227 



Doris lllummnfa, Gould, Tnv. INfass. (1st ed.) 4 (1841). -De Kay, N. Y. Moll. 8 (1843). 

 Polycera illuminata, Sxi.MrsoN, Check Lists, 4 (1860). 



Animal ])rismatic, somewhat four-sided, the back arched, some- 

 what contracted back of the tentacles, a little dilated around the 

 gill-tuft, then rapidly tapering to a point. Color pale yellowish, 

 thickly dotted with green so as to give a general greenish effect. 

 A sharp ridge or narrow fringe runs along the sides of the back, 

 bearing six tubercles on each side, and making the body quadrate 

 between the tentacles and gills ; another range of tubercles runs the 

 whole length of the animal on the median line ; also scattered tu- 

 bercles on the sides and tail, more or less in lines ; all these are 

 sulphur yellow. The head is nearly semicircular, and with a hood 

 having six projecting points on each side. Mouth strongly pursed. 

 Tentacles short, moderately clubbed, Avith twelve or thirteen oblique 

 crowded laminas. Eyes very minute. Branchial plumes three, with 

 a small supjjlementary one each side, doubly pinnate, having at the 

 base three elongated yellow tubercles. Foot pale, square in front, 

 slightly dilated at angles, advancing a little liefore the head in pro- 

 gression, sides parallel, rather blunt posteriorly. Spiculte of the 

 skin elongated, cylindrical, knobby. Length, three fourths of an 

 inch ; breadth, one fourth of an inch. 



Found in the Bath-house, Craigie's Bridge, Boston, and at Aspin- 

 walFs Mast-yard, in considerable numbers. It is a very common 

 animal on the English coasts ; has been found in Sweden by Pro- 

 fessor Loven ; and was originally discovered by D'Orbigny, near 

 Rochelle, France. 



It is a beautiful animal, rather sluggish in its movements. Alder 

 states that it inhabits the region of Corallines, and is found almost 

 exclusively on Gemellaria loriculata, which appears to be its favorite 

 food. 



Ocniis DOSIIS, LiN-N-.Eus. 1758. 



Body elliptical. Cloak covering the head and foot. Dorsal ten- 

 tacles two, laminated, retractile within cavities. Oral tentacles two, 

 various or wanting. Branchiae on the median line of the back. 



(Section 2. — Branchige simply pinnate, set separately in an open 

 circle, non-retractile ; oral tentacles replaced by a veil. Lamel- 



LIDORIS.) 



