Notoscopelus kroyeri dorsal fin has 21 or 22 soft rays, the anal fin has 18 to 20 soft rays and the pectoral fins have 12 to 13. Like other members of the genus, it has many small photophores on the sides and flanks of the fish, arranged in a fashion that is characteristic to this species. Mature males have a gland consisting of eight or nine luminous scale-like segments on the dorsal surface of the caudal peduncle, but they lack the bioluminescent patches on the cheek and above the eye that are characteristic of some members of the genus. "N. kroyeri" is
Avicularium shape as the autozooids. Interzooidal avicularia are wedged between autozooids but do not replace an autozooid. Adventitious avicularia are placed somewhere on the external (frontal) wall of an autozooid and are usually much smaller. The 'birds-head' avicularium (e.g. "Bugula") is elevated above the colony by a stalk (peduncle). A zooid where the operculum is modified into a very long, hair-like structure is called a vibraculum. The cylcostome family Eleidae, which convergently evolved an opercular structure during the Early Cretaceous to Paleocene, also possess avicularia-like zooids. Avicularium The avicularium (pl. avicularia) in cheilostome bryozoans is a modified, non-feeding zooid. The operculum,