Julia exquisita (Gould, 1862)  

Original Description of the animal (Kay, 1962, Contribution No. 172, Hawaii Marine Laboratory):

"The body is long and slender, the foot nearly as wide as the neck. The head and neck extend some 2 mm from the anterior edges of the shells when the animal is moving. The rhinophores are slender, squared off at t he tips, and at their bases is the slightly elevated eye prominence. The oral tentacles do not extend beyond the edge of the foot, and are prominent, rounded structures. The anterior edge of the foot is bilabiate, wide, ext ending laterally to the oral tentacles, and the sole is grooved its whole length by faint grooves. The foot is flattened posteriorly and medially.

The body is dark green, sparsely ornamented on the neck and foot with small white patches ringed with brown and with similar but much more prominent single patches on the rhinophores. The mantle is also green, but has horizontal brown and white bands at the hinge line and at the distal edge of the shells. The sole of the foot is lighter green than the rest of the animal. The eye prominence is white, the eyes black. J. exquisita resembles the previously described bivalved gastropods in general organization of internal anatomy.

The shells from living animals are bright green, with narrow, radiating, interrupted bands of red-brown and white extending from the hinge to the ventral margin. Beachworn specimens may be white. The hinge consists of a shelf which forms posteriorly a toothlike knob on the left valve and a depression in the right valve into which the left valve fits.

The animals were found in sand patches on small rocks some 3 f t under water. Three genera of algae also occurred on the rocks: Laurencia, Gracillaria, and Gracillariopsis. The animals readily crawled and hung by mucous threads on all three genera of algae when confined t o aquaria in the laboratory. Although the described species of Berthelinia and Midorigai are associated only with the alga Caulerpa, it has not been possible to associate ]. exquisita with a single algal genus."

4.0 -6 mm.