All the species already mentioned, except the black tern, have much the same general coloration species as " nostrati lingua sterna appellata."
Ileymons, the hypopharynx represents the sterna of all the jaw-bearing somites, but other students consider that it belongs to the mandibular and first maxillary segments, or entirely to the segment of the first maxillae.
In the abdominal exoskeleton the segmental structure is very clearly marked, a series of sclerites - dorsal terga and abdominal sterna - being connected by pale, feebly chitinized cuticle, so that considerable freedom of movement between the segments is possible.
It is without doubt the Sterna of Turner, and in former days was abundant in many parts of the fen country,' to say nothing of other districts.
Lameere's classification is founded on the number of abdominal sterna, the nervuration of the wings, the number of malpighian tubules (whether four or six) and other structural characters.
Roseate Terns Sterna dougallii have returned to the site after an absence of six years with 2 breeding pairs recorded for 1997.
The first and second abdominal sterna are often suppressed or reduced, on account of the strong development of the hind-legs.
The Little Tern (Sterna albifrons) is one of Britain 's rarest breeding seabirds.
The Little Tern (Sterna albifrons) is one of Britain's rarest breeding seabirds.
The more common sea-birds are the Sula variegate or guano-bird, a large gull called the Larus modestus, the Pelecanus thayus, and the Sterna Ynca, a beautiful tern with curved white feathers on each side of the head.
They may be distinguished from the Malacodermata by the presence of only five or six abdominal sterna, while six malpighian tubes are present in some of the families.
This last is the beautiful roseate tern, Sterna dougalli; the other is the black tern, Hydrochelidon nigra, belonging to a genus in which the toes are only halfwebbed, of small size and dark leaden-grey plumage.
To Turner's name, repeated by Gesner and other authors, we owe the introduction by Linnaeus of Sterna into scientific nomenclature.