186 PROCEEDINGS OF THE AMERICAN ACADEMY. 



The Pyrgos coastal plain on the western end of the Peloponnesus shows char- 

 acteristic intrenching consequent streams.* 



The Sykonia coastal plain, south of the gulf of Corinth, is much complica- 

 ted by faults, t The streams are frequently lost in crossing the gravel of the 

 youngest step. 



Adolescent dissection: Eastern Italij. — Eastern Italy, nortli of the " spur," from 

 Pesaro to Termoli, is a coastal plain of Pliocene strata \ dissected by consequent 

 streams now aggrading (Ital., 140, 111, 147, 148, 155). There is indication of cap- 

 tures, particularly in tlie Pescara, Saline, Vomano, and Sangro rivers, but study 

 upon the ground is needed for proof. Several streams siiow cutting of the right 

 bank more than the left, Biferno, Fortore, Sangro, Pescara, and Tavo. 



Many portions of the Atlantic and Gulf plains of tlie United States, and of the 

 North German plain show characteristic adolescent dissection. 



Mature Dissection: Eastern Virginia. — The form of the surface of the dissected 

 Neocene strata east of Riclimond, Virginia, indicates mature dissection. Tlie 

 slight drowning of the streams indicates that since dissection there has been an 

 episode of depression. 



A portion of the coastal plain of southern Sicily where there is the least defor- 

 mation shows quite typical mature dissection (Ital. and Sicily, 272). 



Adjustment of Drainage. — A characteristic feature of maturity is the 

 adjustment of streams according to the structure of the region. The 

 most perfect mature adjustment will result from (1) considerable diver- 

 sity in the size of the initial consequent streams ; (2) considerable alti- 

 tude of the land-mass ; (3) considerable diversity of resistance in the 

 strata that are cut through by the streams; aud (4) a significant amount 

 of inclination in the strata. § Two successive cycles of uplift will give 

 more complete adjustment than a single cycle. 



8. Fading Elevated Shoreline. 



Lake Shorelines. — Although some of the finest known examples of 

 initial elevated former shorelines occur upon shores abandoned by lake 

 waters, nevertheless these forms as seen to-day have entered their se- 

 quential stages and are fading away. This fact has not been forced upon 

 the reader's attention in the articles upon lake shorelines, and he is left 

 to infer that an elevated former shoreline remains as it was left by the 

 retreating water. Of course the shoreline of a lake, whose water has 



* Dr. A. Pliiiippson, Der Peloponnes ; topograpliical and geological charts, 

 sheet I. section IV. ; text, 321-323. 



t Loc. cit., sheet II. 118, 153; also see Der Isthmos von Korinth, Z. d. G. f. E., 

 1890, XXV. 1-98. 



\ Carta Geologica d' Italia, 1 : 1,000,000, Koma, 1889. 



§ W. M. Davis, Lond. Geog. Jour., 1895, V. 133, 134. 



