The jackal, like the fox, has an offensive odour, due to the secretion of a gland at the base of the tail.
Orifice of coxal gland situated between the coxae of the 5th and 6th appendages.
The essential feature of the asymmetry of Gastropoda is the atrophy or disappearance of the primitively left half of the circumanal complex (the right half in sinistral forms), including the gill, the auricle, the osphradium, the hypobranchial gland and the kidney.
Other glands opening on or near the foot are: (I) The suprapedal gland opening in the middle line between the snout and the anterior border of the foot.
Under side of the uplifted genital or first opisthosomatic somite of the female; g, genital aperture; p, pitted plate, probably a gland for the secretion of adhesive material for the eggs; 1, the edges of the lamellae of the lung-books of the first pair.
The alkaline gland is an irregular tube with a single cellular layer, its duct opening alongside that of the acid reservoir.
In them the foot has a flat ventral surface used for creeping, as in Gastropods, the byssus gland is but slightly developed, the pleural ganglia are distinct, there is a relic of the pharyngeal cavity, in some forms with a pair of glandular sacs, the gonads retain their primitive connexion with the renal cavities, and the otocysts are open.
In the allied genus Cyclas, a byssus gland is formed in the foot and subsequently disappears, but no such gland occurs in Pisidium.
In the mammary gland during lactation or in sebaceous glands, caused by increased functional activity.
In common with the other monotremes, the male echidna has its heel provided with a sharp hollow spur, connected with a secreting gland, and with muscles capable of pressing the secretion from the gland into the spur.