684 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



Coloration. — Plain olive or olive-brown above, sometimes becoming 

 grajnsh on head; beneath buffy or cinnamomeous, obsoletely streaked 

 anteriorly with grayish; plumage very lax, the pileum subcrested. 



Ni (I ifi cation. — Nest in low bushes, of the usual open or cup-shaped 

 type, lined with hairs; eggs (3 to 5) plain pale blue. 



Range. — California and coast of Oregon. (Monotypic.) 



Although the characters of the single genus which constitutes this 

 family are in the main intermediate between those of the Paridae 

 and Troglodytidjfi they are not all so, and there can be no question 

 that it is an isolated type and should, to have consistent rank with 

 other Oscine groups, be regarded as a distinct family. This is clearly 

 the case so far as American and European groups are concerned; but it 

 is possible that some so-called '•'Timeliine'"' form of central or south- 

 ern Asia may be found to be nearly related. 



The osteological structure of Clmmxa, has been carefully studied 

 both by Dr. Shufeklt" and Mr. Lucas,^' and they agree that of the sev- 

 eral genera belonging to the Paridai and Troglodytidas with which 

 they compared it, ^ Cliamxa comes nearest in its osteological charac- 

 ters to PsaltTi2jaru><. Mr. Lucas summarizes the results of his inves- 

 tigations as follows: 



Craniologically Chamsea is much like Psaltriparus, and in those points in which 

 Psaltriparus differs from Parus, by just so much does it approach Chamsea. 



This bird has an open interorbital septum, a large cardiform vacuity at the exit of 

 the olfactory nerves, no maxillo-premaxillary nor cranio-facial hinge, elongate ellip- 

 tical narial oj^enings, and the external process of the nasal continued but a short 

 distance along the i^remaxillary. 



All these characters, save the last, are found in the Wrens as well as in P.?alfripa.ms, 

 and j)robably iu numberless other Passeres and simply illustrate the great similarity 

 of structure obtaining in the order. 



In the "Wrens, the external process qf the nasal runs nearly the entire length of 

 the narial ojiening, there is usually a small, laminar lachrymal present, and the 

 maxillo-i^alatines have a peculiar hamate form and are nonpneumatic. 



In Cliamiva, as in the Paridx, the maxillo-palatines are pneumatic although the 

 shape of these processes differs in the two groups. 



The shoulder 'girdle of Chamsea is extremely feeble, the keel of the sternum being 

 lower than in Psaltriparus minimus, and the wing much shorter than in Parus 

 carolinensis. 



The distinctions between the shoulder girdle of Chamsea and the Titmice are teleo- 

 logical rather than morphological, and this is equally true of the same parts in the 

 Wrens and Titmice, the Wrens being narrow-chested, weak-armed birds, while the 

 Tits are sturdy, full-chested, and strong-armed. 



Like the Wrens Chamsea has the ridge running upward from the coracoid almost 



« On the position of Chumiea in the System. By R. W. Shufeldt; Journ. of Morph. , 

 iii, no. 3, 475-502. (See Allen, The Auk, vii, 1890, 278. ) 



^ Notes on the Osteology of the Paridpe, Sitta, and Chamtea. By Frederic A. 

 Lucas, Assistant Curator of the Department of Comiaarative Anatomy. Proc. U. S. 

 Nat. Mus., xiii, 1890, 337-345, pi. 27. 



^Dr. Shufeldt included in his comparison also the genera Cert It la, Reguhis, PoUop- 

 tila, and Accentor. 



