20 THE VOYAGE OF H.M.S. CHALLENGER. 
becomes more fleshy, and slightly grooved above, especially anteriorly. The sides more- 
over are edged by a series of large triangular backwardly directed papille, extending 
forwards for about the back half of the length of the tongue, but in Puffinus to nearly 
its apex. In Puffinus brevicauda (fig. 18) there are, in addition, four longitudinal fairly 
regular rows of such papillze developed on its dorsal surface, those nearest the middle 
line being the biggest. 
In the species of the genus Diomedea (fig. 7) the tongue is also similarly covered 
above, pretty uniformly, with spines, best developed on the dorsum a little behind the 
apex of the organ, but is much shorter in form, being of an elongated cordate shape. In 
Phebetria (fig. 8), on the other hand, the tongue is much more pointed and elongated, 
being free for about its apical two-thirds, and with the dorsal surface glabrous, the 
spines being confined to its basal margin. In a nestling of this species the tongue 
has much the same shape, but is covered for the greater part of its extent above by 
spines, as in Diomedea: these must therefore disappear as the bird reaches maturity. 
In Thalassiarche the tongue is somewhat intermediate in shape, though most resembling 
that of Phebetria. Pagodroma (fig. 14) has a very elongated, tapering tongue, with its 
base and lateral margins for about their posterior quarter spinulose. The tongue of Daption 
(fig. 12) is much broader and more fleshy ; the spines are small, and almost confined to 
its base, with only a few very obsolete ones towards the posterior angles laterally. It is 
only free for a little more than a quarter of its length. Prion (fig. 13) is similar, but 
the tongue is more fleshy, and the spines are smaller and quite confined to the base: the 
apex is also only free for a very small extent. In Prion vittatus the tongue becomes 
extremely large and fleshy, occupying the whole of the wide space between the rami of 
the mandible. Aecpetes antarcticus (fig. 11) has a tongue very like that of Pagodroma, 
but of course larger and less elongate: that of Thalasswca glacialoides is very similar, 
but longer a little than that of Aezpetes. In all these forms the tip is blunt or emar- 
ginate, with a slight dorsal groove apically. Fulmarus has a more fleshy tongue of the 
same type, with a distinctly emarginate end, and a more evident groove, extending for 
two-fifths of its length. 
In Ossifraga gigantea (fig. 10) the tongue is very elongated,—three inches long,— 
and narrow proportionally. Its apex is slightly emarginate, and there is a deep groove 
for about two-fifths of its length, and traceable further back to the base of the tongue. 
The base has a fringe of pointed spines, which are continued, of smaller size, along the 
lateral margin for some way, there being some very much smaller spines developed 
inside them on the borders of the tongue for about an inch, though not reaching the 
posterior angles of the organ by half that extent. 
(lessont and mollis) examined by me nor with any of my young specimens of the so-called Wstrelata brevirostris, these 
resembling rather the species just named. This tongue is remarkable for having no spines laterally, those of the base 
being well developed, and for its narrow and deeply grooved form and slightly emarginate tip. In spite of its label, it 
belongs, I strongly suspect, to some species of the Laride. 
