92 BULLETIN 82, UNITED STATES NATIONAL MUSEUM. 



Lateral faces oj the radials. — The faces by which each radial is in aj)positioii with 

 the radials on either side (see figs. 549a, 5516, and 552, pi. 5). 



Lateral j)rocesses. — In certain of the conuitnlids, ventrolateral or dorsolateral 

 processes dcveloj)ed along the division series and on tlie fii-st or first two 

 brachials, one to each ossicle, of wliicji llie former assist in supporting the disk 

 (see fig. 87, p. 143). 



Lateral surface. — Of the centrodorsal ; the entire surface between tlie dorsal pole 

 and the ventral rim (see figs. 220-222, 224, p. 243, and pp. 229-232). 



Law of WacJismuth and Springer. — A law by tlie a})i)lication of which the presence 

 or absence of infrabasals may be determineil; it reads as follows: 



"1. In species with infrabasals, whenever the column is jjcntangular, its 

 longitudinal angles are directed interradially, the sitlos and columnar cirri 

 radially; on the contrary, in species with basals only, those angles are radial, 

 the sides of the column and the cirri interradial. 



"2. When there are infrabasals and the column is pentapartite, the five 

 sections of the column are interradial, the longitudinal sutures radial, the radi- 

 ation along the axial canal radial; but the opposite is the case when basals 

 only exist." 



Exceptions occur in regard to the outer angles and sides of the column, 

 and the orientation of the axial canal, due to modification by secondary 

 growth. 



Left anterior arm. — The arm or ray next to tlie left of the anterior arm or ray, as 

 viewed ventrally, that is, with the disk uppermost ; it lies between the anterior 

 and the left ])osterior arms or rays (see Axis and Orientation). 



Left anterior interradial area. — See Axis and Orientation. 



Left anterior postr-radial series. — See definition under Left anterior arm. 



Left anterior ray. — See definition under Left anterior arm. 



Left anterolateral ray. — In the Comasteridae (see Orientation 3). 



Left lateral interradial area. — See Axis and Orientation. 



Left posterior arm. — The arm or ra}' immediately to the left of the anal area; the 

 disk ambulacra leading from its base form the left boundary of the anal area 

 (see Aids and Orientation). 



Left posterior post-radial series.— See definition under Left posterior ar^m. 



Left posterior ray. — See definition under Left posterior arm. 



Left posterolateral ray. — -In the Comasteridse (see Orientation 3). 



Ligament pit. — The (usually) well-marked ])it or depression situated in the doi-sal 

 ligament fossa just within (below) the center of the transverse ridge (see figs. 

 9-11, p. 65, 31, 32, p. 71, and 431, 432, p. 349, and p. 114). 



Lips. — In the Comasteridw the circumoral ring is more or less differentiated into a 

 smaller anterior and a lai'ger posterior j)ortion instead of being uniform all 

 around as is the case in the endocyclic species; the two lobes thus indicated 

 are commonly referred to as lips. 



Longitudinal axis. — See Axis 3. 



