The " tongue," for example, is short and obtuse or emarginate in Colletes and Prosopis, while in all other bees it is pointed at the tip. But in Andrena and its allies it is comparatively short, while in the higher genera, such as A pis and Bombus, it is elongate and flexible, forming a most elaborate and perfect organ for taking liquid food.
- Pleurodont; solid teeth; anterior part of tongue slightly emarginate and retractile, and covered with flat papillae; no osteoderms. Mexico.
- Pleurodont; teeth solid, sometimes (Ophiosaurus) grooved; anterior part of tongue emarginate and retractile into the posterior portion; osteoderms on the body, and especially on the head where they are roofing over the temporal fossa; entirely zoophagous and ovo-viviparous.
The jugal is without an inferior angle, and extends forwards to the lachrymal; the palate is contracted in front and deeply emarginate behind; the incisors are short, and the molars divided by continuous folds into transverse plates; and the two halves of the lower jaw are welded together in front.