...as well as: 
Zwilling, Leonard. 1992. Homosexuality as seen in indian buddhist texts. In Buddhism, Sexuality, and Gender. Ed. José Ignacio Cabezón. Albany: University of New York Press
a google-preview of which can be found here: http://tinyurl.com/cpaptdk

there are also some informations on these topics from the point of medical+sexological literature scattered throughout RP Das' monumental work (fortunately endowed with a detailed index):
Das, Rahul Peter. 2003. The Origin of the Life of a Human Being : Conception and the Female According to Ancient Indian Medical and Sexological Literature. Delhi: Motilal Banarsidass Publishers.
see, for example, his discussion of Skt terms. napuṃsaka and paṇḍaka

Andrey  


On 09.05.2012, at 17:45, Hartmut Buescher wrote:

... studies of non-standard sexualities in ancient India (..., transsexualism, ... etc.)

Not least also in view of the significance of this issue in the MBh,
Robert P. Goldman's
”Transsexualism, Gender, and Anxiety in Traditional India”
[in: Journal of the American Oriental Society 113.3 (1993): 374-401],
providing a survey of ”a number of salient examples of transsexualism
drawn from the religious and mythological texts of ancient and medieval
India” (further references in his bibliography), is likewise rather indispensible.

HB