no. 1658. ALCT02V I/.'/ I OF THE C ILIF0RN1 1 V CO 1ST XlTTIXd. fiCjl 



No. 11 lias a number of more <>r loss aborted Leaves springing irreg- 

 ularly from the mass of zooids on the ventral side, as shown in 

 Plate LXXXI\ , fig. 8. The calyces on these aborted leaves appear 

 to be quite normal. In one case there is a single calyx springing from 

 the line of juncture of the leaf base and rachis on the ventral side. 

 All of these abnormalities are on one side of the hare ventral space. 



ANATOMICAL STUDY OF SPECIMEN No. 1. 



Stem flabby and much corrugated longitudinally, enlarging imme- 

 diately below junction with rachis to a diameter of 1.9 inches ami 

 narrowing gradually to the proximal end. There is a distinct opening 



at 1 he lower (Mid. 



Axis (dissected out from dorsal side), proximal end (i.7 inches from 

 the proximal end of stem. Axis extends from this point to one 3.2 

 inches from distal end of feather. The axis is overlaid by a longi- 

 tudinal membrane extending across the stem cavity and adherent 

 below to the inner surface of a similar membranous sectum on the 

 ventral side. It is therefore situated in a separate chamber ninning 

 lengthwise of the feather and adherent to the dorsal and ventral walls 

 of this chamber, which it divides into two lateral halves. This, w hich 

 I will call the "axial chamber," is quite small and inconspicuous, and 

 mighl readily be overlooked in certain sections. There is a similar, 

 but larger, longitudinal chamber between the axial chamber and the 

 dorsal wall of the stem, and another which is ventral to the axis. 

 There are thus four chambers in all : The right axial, left axial, dorsal, 

 and ventral. 



The dorsal chandler is much the largest, the ventral next in size, 

 and the two axials much smaller. This is the condition in a section 

 near the distal end of the axis. Farther down, where the leaves are 

 best developed, the Four chambers change their relative size. Here 

 the dorsal is largest, the two axials next, and the ventral smallest, as 

 shown in the lower section illustrated in fig. 2, Plate LXXXY. 



The total length of the axis is 7. ( .l inches and its greatest diameter 

 0.14 inch. It is square in section, tapering gradually at each end. 



A cross section of the stem just below t he rachis, but not below t he 

 proximal end of the axis, is shown in the upper left-hand figure in 

 tig. 2. Plate LXX.W. Here the four chamber- are almost equal, the 

 axis being approximately in the center. 



A similar section taken through the stem below the axis cylinder 

 and about 3.2 inches from the proximal end of the stem is nearly 

 round and L.3 inches in diameter. The wall is about 0.24 inch thick 

 and is bounded l>\ an outer and an inner membrane, as shown in the 

 upper right-hand section in fig. 2, Plate LXXXY. Between these 

 membranes is a vesiculated structure, well shown in the photograph. 

 Here the stem cavity is divided by a longitudinal membranous par- 



