FAMILY GLAUCID£ — EOLIDIA. 9 
papillose, with strong transverse folds. Jaws angular. Tentacula arising from the back of 
the head, and received intoa round sheath which terminates in five unequal branches. Five 
pair of dorsal gills, all susceptible of being retracted into the body of the animal, leaving in 
their places small tubercles. Sexual orifice closed by a conical valve, attached before. Anal 
orifice between the first and second pair of dorsal gills. 
Color. Rufous brown, occasionally dark brown, with patches of white on the back between 
the branchial tufts. Foot white, diaphanous. 
Length, 3°5. 
Mr. Couthouy found this animal about the bathing-houses and timber-docks in Charles river ; 
and as it differed in many respects from the T. arborescens of Cuvier, he described it as a 
new species. Recently Dr. Gould has referred it, on the authority of Dr. Lovén of Stock- 
holm, to the species described by Cuvier. 
FAMILY GLAUCID:. 
Animal furnished with two and sometimes three pair of tentacula. Gills strap-shaped, or in 
the form of cirri. 
GENUS EOLIDIA. Cuvier. 
Body oblong, slug-shaped, gelatinous, terminating in a point behind. Head distinct, with four 
tentacula above, and occasionally two on the sides of the neck. Gills prominent, composed 
of conical or flattened cirri arranged in longitudinal series along the back. Sexual and anal 
orifices separate, on the right side. 
Eo.ipIA BOSTONIENSIS. 
PLATE V. FIG. 96.—(CABINET OF THE LYCEUM.) 
Eolis bostoniensis. CoutTHovuy, Bost. Jour. Nat. Hist. 
E. rufibranchialis? Govxp, Invertebrata of Mass. /p. 6. * 
Description. Body oblong, with a slight protuberance on the centre of the back. Head 
orbicular, short, with four tentacula: two lateral and longest; the other pair on the back of 
the head, with the eyes near their base. Beneath the mouth are two other appendages re- 
sembling tentacula. Mouth large and fleshy. Lips hemispherical. Branchie tubular, arranged 
in five clusters on a side. Sexual orifice just behind the anterior cluster of gills on the right 
side ; the vent near the back, between the third and fourth branchial group. 
Color. Brownish white : lateral tentacula, lake tinged with blue ; the other pair dark flesh- 
color. Gills brown tipped with white. 
Length 1°5. 
Fauna — Part 6. 2 
