THE VOYAGE OF THE ' CHALLENGER/ 415 



losed to the frontal above and the ethmoid anteriorly (PI. XXII. figs. 1, 3). 

 It is hollow, with one large, and several small external apertures. 



In connection with the descending limb of the lachrymal bone there is 

 often developed a peculiar ossicle, named by Brandt (cf. supra, p. 367) 

 who was the first to describe its existence in Diomedea brachyura and 

 Puffinus major, the " ossiculum lacrymo-palatinum," from its connection 

 with those two bones. 



Its nature and relations in the group have subsequently been more Zool. Ohall.] 

 extensively investigated by Eeinhardt (vide supra, p. 371), who calls it the E t xl ^ vol '44' 

 " os crochu." 



When best developed, as in the Albatrosses, the "ossiculum lacrymo- 

 palatinum " is a small styliform ossicle of nearly cylindrical (as in 

 Thalassiarche culminata, PI. XXI. fig. 7) or somewhat lamellar (Phcebetria 

 fuliginosa, PI. XXI. fig. 8) shape, attached above by an articulation to the 

 inner face of the descending limb of the lachrymal bone, and below 

 connected by a ligament to the upper surface of the palatine bone. 

 Seen from the side, in the dried skull (vide PI. XXII. fig. 1) the bone is 

 visible below the malar arch. It lies, in the recent state, in a cavity 

 between the nose and the roof of the mouth, in an oblique position, 

 pointing downwards and inward. This bone is present in all the genera 

 and species of Albatrosses examined by me, as well as in Thalassiarche 

 clilororhyncha, as mentioned by Reinhardt. In the Oceanitidse, in 

 Procellaria and Cymochorea, as well as in Daption and Pagodroma, its 

 place is taken by a narrow ligament in which there is no ossification at 

 all. In Bulweria, Pelecano'ides, Fulmarus, Thalassceca, and Ossifraga 

 there is a similar ligament, with a small, more or less ossified nodule of 

 bone lying in it, only connected by connective tissue with the surrounding 

 bones. In Aeipetes, Prion, Puffinus, Majaqueus, Adamastor, and (Estrelata 

 it is small and delicate, articulating with the lachyrmal above, and 

 ending freely (in the cleaned skull) below. 



It is interesting to observe that a very similar bone, both as regards 

 shape and position, occurs in the genus Fregata as already pointed out 

 by Reinhardt, whose observation I have been able to verify. But it also 

 occurs in forms so different from these as the Musophagidse, many 

 Cuculidae, Chunga and Cariama, as well as in some Laridae and Alcidas, 

 so that its presence is obviously of no particular taxonomic value. 

 Professor Parker informs me that its precise morphological significance is 

 at present rather uncertain. 



The palate (vide PI. XXII. figs. 2 and 4) is always more or less incomplete 

 below, the fissure dividing it being, by the less degree of inward 

 developrnentof the maxillary processes of the premaxillae, and of approxi- 

 mation of the inward edges of the maxillo-palatines and palatine bones, 

 longer and wider in the smaller than in the larger forms. 



The inaxillo-palatine processes are concavo-convex lamellae, extensively 



