296 PEOFESSOE W. K. PAEKEE ON THE 



Passing on to details, I may observe that my study of this skull has been from a 

 nearly ripe nestling (see Plate LII. figs. 1-3), from well-fledged young, and from the 

 adult. The youngest of these suits my purpose best ; it was twice as much developed 

 as the young Martin whose palate has just been described i. 



The skull is short and broad; the basitemporal (b.t) a very narrow band; and this 

 part of the basis cranii is very flat, and carinate forwards, as in Caprimulgus. Here 

 also, ready to break out, are the basipterygoids {h.pg) ; here they are mere angulations 

 of the upper wings of the basisphenoid, and they even get rounded off in the adult. 

 The rostral region of the basis cranii (parasphenoid, ])a.s) is much more thick and 

 spongy than in the Swallows, but much less than in the Goatsucker, and is exactly 

 intermediate. 



The pterygoids Qj(/, e.2)g) are more Hirundine ; they are long, slender, gently arcuate, 

 and with a fuller epipterygoid, as in C'apmnulgus. Their anterior spatula and meso- 

 pterygoid segment are normally Passerine (fig. 2, pg, ms.pg). The palatines are pecu- 

 liar, but they are Passerine. The transpalatine bone {t.pa) is scarcely invested by 

 ectosteal layers, and is distinct ; it is a flat hook. The main palatine bone is peculiar. 

 The postpalatine region is bevelled off ; it was lessening in the Swallow ; but the edges 

 that run into the interpalatine spike are well incurved round the postnarial channel. 

 The isthmus is of great extent ; but the interpalatine spikes run a distance in front of 

 it equal to its breadth {i.pa) ; they overlap the maxillo-palatines largely, whereas it is 

 the rule for the contiguous parts of these processes to be tied together by a considerable 

 ligament ; in this the Swift is peculiar. A new and Cypseline character is seen in the 

 angulation of the main palatine bar in front of the distinct transpalatine, making the 

 bar bidentate as it flattens out towards the jugum. In front of this second projecting 

 angle the bar is a sinuous plank,, convex below, concave above, and moderately strong ; 

 its fine point overlaps most of the delicate palatal process of the praemaxillary, on its 

 mner side, as in the Passerines. 



The broad part of the ethmopalatine plate {e.pa) is only two thirds the extent of the 

 lower plate ; but its spurs are of extreme length, and, contrary to the Passerine norma, 

 they lie not only above, but on the inside also, of the long crura of the narrow-waisted 

 ox-faced vomer. As in the Swallow and Goatsucker, the prsemaxillary nasal processes 

 and the nasal bones become extremely thin where they are let into the frontals. The 

 relative size of the prsemaxillary is here reduced to the utmost degree for a bird, and 



with the Swift, a miracle of flying-power, which, in deeds, if not in words, says : — 



" I drink the air before me, and return 

 Or ere your pulse twice beat." 



' With these figures compare those of the larger " Pissirostres," e. g. Caprimulgus and Podargus (Trans. 

 Linn. Soc. ser. 2, Zool. pi. 21. fig. 8, and pi. 23. figs. 6, 7). 



