952 



TECTRICES 



lapping wing-coverts were shewn many years ago by Sundevall ^ to 

 have a taxonomic value, and the later researches of Mr. Goodchild 

 {Troc. Zool. Soc. 1886, pp. 184-203) have carried the matter further. 

 The latter distinguishes seven different types of arrangement in the 

 wing-coverts : 



1 . All the Upper feathers overlap proximally : only 3 or 4 

 transverse rows owing to the absence of the Lesser coverts, which 

 are represented by enlarged marginals — CypselidsB and Trochili. 



2. Lesser coverts absent, marginals enlarged and overlapping 

 proximally : Middle Upper coverts reduced to one row and over- 

 lapping distally — Oscines. 



3. One row of Middle and 5 or 6 rows of Lesser Upper coverts, 

 all overlapping proximally — CucuUdm, Musophagidx, Coracias, Indi- 

 cator and Caprimulgus. 



4. One row of Middle and from 2 to 4 rows of Lesser coverts 

 overlapping distally — Picidas, Rhamphastidx, Akedinidx and Chasmo- 

 rhynchus. 



5. The Middle row and from 3 to 6 Lesser rows overlap distally, 

 except the feathers toward the elbow, which overlap proximally — 

 — the meeting-place of these two differently-disposed groups being 

 generally very conspicuous. This is the most common and possibly 

 the most generalized type, from which all the rest may be derived, 

 and occurs in Falconidse, Psittaci, Striges, Herodii, Phalacrocorax, 

 Anseres, Meleagris and many Gallinse, Goura, BalUdee, Limicolm, Ciconia, 

 Platalea and Ibis. 



6. The whole row of Middle coverts overlaps proximally ; numer- 

 ous rows of Lesser, but those which overlap distally are restricted 

 to a patch on the middle of the Upper surface — Columha, Ptero- 



' didse, Laridse, Sula, Serpentarius. 



7. Numerous rows of Upper coverts all overlapping proximally 

 — Myderia, Leptoptilus, Fregata, Plotus, Diomedea, Ossifraga, Puffinus, 

 Cathartidse. 



Considering that all the birds of this last type are remarkable 

 for the length of their wing-bones, and consequently the great 

 number of remiges, as well as the fact that other Ciconix, Tuhinares 

 and Steganopodes belong to a different type, it seems reasonable to 

 think that the character of this group is the result of specialization, 

 and has been independently acquired, without indicating any rela- 

 tionship. On the other hand, the agreement between Cypselidx 

 and Trochili, Cohimbx and Pterodidse, both indicating a reference to 

 Limicolse, and the similarity between Cathartidse and Steganopodes as 

 well as Pelargi are at least suggestive of taxonomic value ; but for 

 further information Mr. Goodchild's treatise, -svhence some figures 

 are here introduced, should be consulted. 



^ K. VetensTc.-Ak. Handl. 1843, pp. 303-384. A translation of this memoir by 

 Dallas appeared in Tlie Ibis, 1886, pp. 389-457i pis. x. xi. 



