Biological Investigations of the Deep Sea. 33.

Opisthobranchs from the Southwestern Caribbean Sea

In the southwestern Caribbean Sea, off the coasts of Colombia and Panama, the research vessel John Elliot Pillsbury collected 13 species of opisthobranchs. New species and subspecies are: Scaphander darius, Akera bayeri, Peltodoris hummelincki igla, and Nuvuca lurca, g. n., sp. n. S. darius has a male organ similar to that of S. lignarius, but the penial papilla is beset with warts. A. bayeri is the first American representative of the genus Akera. By its dart and a gland annexed to the male organ, Nuvuca approaches Audura and Jorunna. Of the known species in the collection, one Philine has an immersed spire and each of the paired gizzard plates nearly the shape of half the unpaired one, like Ph. infundibulum. The other Philine is identical with Ph. alba from South California. Now it has been found in the Mosquito Gulf (295-109 m), hence is an amphi-American warm-water species.