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SMITHSONIAN MISCELLANEOUS COLLECTIONS 



[VOL. 47 



camane. In others, one or more of the interior walls crowd upon 

 this area, and this cavity then becomes very irregular in shape and 

 much reduced in size. However, in all specimens there is more or 

 less of a chamber just beneath the stalk and between the walls of 

 the camarse. 



The camara; occupy by far the larger part of the bulb and are 

 very variable in shape, size, and number. The usual number is 5 or 

 6 (rarely 11), and additional chambers are introduced by bifurca- 

 tion of the roots beneath the 

 stalk. In C. ulrichi they 

 often occur in pairs, and in 

 some individuals there are 4 

 of these small chambers in 

 pairs situated on opposite 

 sides. Such specimens will 

 have 8 or 9 chambers sur- 

 rounding the medio-basal 

 cavity. The greatest num- 

 ber observed is II. Usually 

 the number of camarae is in- 

 dicated on the outside of the 

 theca by constrictions over 

 the walls of the interior. 

 The base of the bulb inside of the more or less high collar is com- 

 posed of 2 sets of plates — one series consisting of larger pieces, fairly 

 regularly arranged, and restricted to the roots that radiate from the 

 stalk ; the other of irregularly shaped smaller plates that fill in the 

 spaces between the root radii. The stalk is generally placed a little 

 eccentrically to the high, most prominent or primary root member. 

 This member usually bifurcates at each end and each division 

 branches once more ; from the lower sides of this medial member are 

 given off from 1 to 3 other secondary branches, each of which again 

 bifurcates distally (see text-figure 43). There are, therefore, 

 around the inner side of the collar, from 12 to 18 and even as many 

 as 22 branchlets, between each 2 of which is situated a more or less 

 large opening to the chambers, there being as many of these openings, 

 4 to 11, as there are chambers. The roots between each bifurcation 

 consist of from 3 to 5 plates, the place of division of the primary 

 root member being occupied by a single wedge-shaped piece, while 

 those on the sides usually have a double plate occupying the same 

 position. The axial canal of the stalk does not pass through the base 

 of the bulb and into the medio-basal chamber, but ends in the primary 



Fig. 43. — View of the base of Camaro- 

 cruius ulrichi; the interior canals of the roots 

 are indicated by broken lines. X 2. 



