lagena
From ZooTerms (Dictionary of Invertebrate Zoology)
neck above; lageniform.
lagena (noun; Latin lagaena, flask): 1. Bottle-shaped; dilated below and tapering to a narrow
2. (Arthropoda: Insecta) In Lepidoptera, the smaller lobe of the spermatheca; may be fused into one organ
See also: utriculus.