Glauconema trihymene n. g., n. sp., a Hymenostome Ciliate from the Virginia Coast*

SYNOPSIS. Glauconema trihymene n. g., n. sp., a marine hymenostome ciliate, is described from the Virginia coast. Morphologic studies were made on specimens treated with the Chatton-Lwoff silver impregnation technic and on animals observed with the phase microscope. Particular attention is given to the buccal ciliature and its importance to generic assignment in the order Hymenostomatida.     

The Sites and Consequences of Melatonin Binding in Mammals

SYNOPSIS. Melatonin, a hormone of the pineal gland, exerts multipleeffects upon the brain-pituitary axis of vertebrates. Amongmammals, the best documented physiological roles of melatonininvolve the photoperiodic induction of reproductive and otherseasonal adjustments. Daylength regulates the effects of gonadalsteroids upon gonadotropin secretion and sexual behavior aswell as the frequency of a neural generator of GnRH pulses.In hamsters, these effects are paralleled by changes in GnRH,AVP and beta-endorphin immunoreactivity, and in opiate receptordensity in the medial amygdala. Autoradiographic studies indicatea high concentration of 2[¹²⁵I]-iodomelatonin binding sitesin the suprachiasmatic nuclei of some photoperiodic mammalsbut not in others. In contrast, such binding sites have beenfound in the pars tuberalis of all seasonally breeding mammalsstudied to date.     

A Description of Cohnilembus verminus from Eniwetok Atoll*

SYNOPSIS. Cohnilembus verminus, a marine hymenostome ciliate, is described from a culture taken at Eniwetok. Anatomic studies were made on specimens treated primarily with the Chatton-Lwoff silver impregnation technic.     

Redescriptions of Uronema filificum and U. elegans*

SYNOPSIS. Two species of hymenostome ciliates, Uronema filificum, and U. elegans, are described from the Atlantic coast. Studies were made on specimens treated with the Chatton-Lwoff silver impregnation technic, and particular attention was given to the buccal infraciliature.