ALBERT

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: 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: 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.

Description: If ground‐water levels of a confined aquifer fluctuate with sea tides, individual values of hydraulic conductivity and specific storage can then be determined. Apparent tidal efficiency and time lag are first calculated from the water level data recorded at an observational device situated inland from the sea, taking into account the response characteristics of the observational device according to criteria established by Hvorslev [1951]. The true tidal efficiency of the aquifer at the seacoast is then determined from the apparent tidal efficiency and used to obtain the specific storage. This and the tidal time lag are utilized to calculate the hydraulic conductivity. The method was tested in Prince Edward Island, Canada, and yielded results compatible with pump test data. This is a simple and inexpensive way to test a confined aquifer in the coastal environment.