Bibliographical Notice. 371. 



racter disappears, and a species of segmentation takes place, the 

 minute granules becoming more closely aggregated together, so 

 as to form irregular and somewhat darker patches within the 

 spherule, whilst the form of the latter is in nowise modified. A 

 representation of these phenomena is given on a largely magnified 

 scale in figs. 8, 8a, and 8 b. 



[To be continued.] 



EXPLANATION OF PLATE IX. 



Fig. 1. Amoeba villosa, showing the position and appearance of the large 

 granular mass, with the true nucleus, and cylindrical form as- 

 sumed by the Amoebae. 



Fig. 2. A specimen in which the contractile vesicle is apparently replaced 

 by a conical-shaped vacuole. 



Fig. 3. The granular mass and villous tuft, showing the infundibuliform 

 tubule. 



Fig. 4. The villous tuft and infundibuliform tubule, with an extruded 

 vacuole (?), and its investiture and sustaining filament of sarcode. 



Fig. 5. An Amoeba with multiple nuclear bodies. 



Fig. 5a. One of these mulberry-shaped nuclei, as seen immediately after 

 extrusion. 



Fig. 6. Encysted ? form, with distinct membranous envelope. 



Fig. 7- One of the true nuclei after isolation from the parent body, show- 

 ing its membranous investiture. 



Fig. 7b. The same, as seen after augmented pressure. 



Fig. 8. Largely magnified portion of an active Amoeba, showing the appear- 

 ance of the sarcode-globules (8a, 86) isolated by pressure. 

 N.B. The whole of the specimens were more or less full of minute 



Crumenulce, with which the material in which they were found abounded. 



BIBLIOGRAPHICAL NOTICE. 



On the Geology and Natural History of the Upper Missouri : being 

 the substance of a Report made to Lieut. G. K. Warren, T.E.U.S. A. 

 By Dr. F. V. Hayden, &c. &c. 4to, Philadelphia, 1862. (From 

 the Transactions of the American Philosophical Society, vol. xii. 

 Read July 19, 1861.) 



This valuable memoir comprises information collected on three oc- 

 casions : — 1st. An account of the geological observations made by 

 Dr. Hayden when associated with Lieut. Warren's Expedition, in 

 the summer and autumn of 185 7, from Bellevue on the Missouri 

 (about 41° lat., 96° long.) to the mouth of the Big Sioux and back, 

 and then across Nebraska to Fort Laramie, then northward across 

 the Black Hills to Bear Peak (about 44° 30' lat., 105° 20' long.), 

 and then south-eastward through the Bad Lands to the Niobara 

 River, and along it to Fort Randall on the Missouri. 2ndly. Geo- 

 logical explorations, by Dr. Hayden and Mr. F. B. Meek, in the 

 north-eastern portion of Kansas territory (between 95° and 98 long., 

 and 38° and 39° 30' lat.), in 1858. 3rdly. Some results of an ex- 

 pedition to the north-west under Capt. W. F. Raynolds, in 1859-60. 



