ALBERT

Description: A new species of occllated octopus, Octopus maya, is described from nine specimens collected in the Bay of Campeche. The species, known only from the bay, was taken during a survey of the octopus fisheries and is the second described species of ocellated octopus from the Atlantic Ocean. It is characterized by a large double-ringed ocellus, large eggs attaining a length of 17 mm, and, in the male, a minute ligula. It is compared with other ocellated species from the Pacific and Indian oceans. A key to the eight species of shallow water octopus of the tropical Western Atlantic Ocean is included.

Description: During the course of an examination of cephalopod specimens of the genus lllex from tropical waters of the western Atlantic, two of us (KM and CFER) discovered specimens that did not conform to the characteristics of previously known species. While working at the Smithsonian Institution on a large collection of lllex from the Chesapeake Bight region as part of a monographic study on the genus, one of us (CCL) encountered additional specimens of the undescribed species.

Description: Observations on egg laying in D. plei are reported. The similarities and differences of the egg deposition process, the egg mass structure and the mode of attachment in other North American loliginid squids are compared with that of D. plei.

Description: Two new species were discovered during the course of a study on the systcmatics and distribution of the world-wide deep-sea squid genus Balhyteiithis. Both species occur in the eastern Pacific Ocean, one from the tropical waters of the Bay of Panama and the other from the cooler waters off southern California. The species are briefly described here so that the descriptions and names will be available for use by workers currently engaged in regional surveys, e.g., that in preparation by R. E. Young, Institute of Marine Sciences, University of Miami. Detailed descriptions will be presented in the more comprehensive study (Roper, 1968).

Description: A new spccics of barred octopus is described from material collected aboard the R/V Pillsbury from off the Caribbean coast of Colombia. It is compared with its nearest relative, O. chierchiae from the tropical eastern Pacific. Descriptions are accompanied by detailed illustrations. Also recorded are: O. defilippi Yerany, O. jouhini Robson, O. vulgaris Cuvier, and Benthoctopus januarii Hoyle. A new key to the known shallow-water octopods of the western Atlantic is included.

Description: The Jeffreys-Bullard theory of the topographic correction to geothermal gradients cannot be applied with confidence if the height of the relief is large relative to the horizontal distance and depth of the measurement points. It cannot be generally applied to shallow probe measurements in the ocean bottom if bold relief occurs on a scale exceeding a few meters, or on continents to observation in shallow boreholes in extremely rugged terrain. In an important special case, where the measurement depth is small relative to the distance to the relief, the ‘superficial’ gradient anomaly may be approximated by the value applicable at zero depth. A fairly general two-dimensional steady-state theory for this case can be based on the solution for heat flux through an inclined plane of arbitrary height and slope angle. These two parameters are easily visualized and represented graphically so that models which approximate or bracket real topography can be identified quickly. The results can be applied to stations on planes, valleys, ridges, or benches bounded by irregular slopes. They are valid for points arbitrarily close to slopes of any height or inclination. Finite slope and curvature of the surface at the station can be accommodated if they are not too great. Even if other theories of the topographic correction are applicable, the present method can be useful, as it leads to rapid estimates by graphical means and to useful limits even if the superficial condition is not satisfied. Curvature in an ocean-bottom temperature profile justifies suspicion of a topographic disturbance from undetected relief. The temperature probe's length should be 2 or 3 times the uncertainty in local elevation difference, and measured curvature should be negligible for reasonable assurance that undetected relief is not causing gradient errors greater than ±10%. Relief not detectable with conventional echo sounders, but of the type observed with deeply towed sounding equipment, can cause heat-flow anomalies of 50–100%, and relatively little curvature will be indicated by probes a few meters long. The very high oceanic heat flows are difficult to explain by undetected relief, but the very low ones are not.