Parathyroid and ultimobranchial glands of the sand boa, eryx johnii Daudin.

Eryx johnii and E. conicus possess two pairs of parathyroid glands (PTG) and one pair of ultimobranchial glands (UBG). The PTG is composed of cell cords and follicles, and is well vascularized. The presence of large vesicles with ciliated and glandular epithelium is the most striking feature of the PTG in E. johnii. Accessory PTG tissues are present. The unique feature of equal sized UBGs in Eryx is their location, i.e., bilaterally parallel and rostrally away from the thyrothymic region. The UBG is composed of follicles and cell aggregates, which are interspersed in a vascularized connective tissue stroma; ciliated and goblet cells are frequently present. The UBG of Eryx shows aging variation, but not seasonal changes; seasonal histological variations are observed in the PTG.