92 BULLETIN 82, UNITED STATES NATIONAL MUSEUM. 



Lateral faces of the radials. The faces by which each radial is in apposition with 

 the radials on either side (see figs. 549a, 551&, and 552, pi. 5). 



Lateral processes. In certain of the comatulids, ventrolateral or dorsolateral 

 processes developed along the division series and on the first or first two 

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

 (see fig. 87, p. 143). 



Lateral surface. Of the ceutrodorsal; the entire surface between the dorsal pole 

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



Law of Wacnsmuth. and Springer. A law by the application of which the presence 

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



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

 longitudinal angles are directed interradially, the sides 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 the left of the anterior arm or ray, as 

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

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



Left anterior interradial area. See Axis and Orientation. 



Left anterior post-radial series. See definition under Left anterior arm. 



Left anterior ray. See definition under Left anterior arm. 



Left anterolateral ray. In the Comasteridas (see Orientation 3). 



Left lateral interradial area. See Axis and Orientation. 



Left posterior arm. The arm or ray immediately to the left of the anal area; the 

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

 (see Axis and Orientation). 



Left posterior post-radial series. See definition under Left posterior arm. 



Left posterior ray. See definition under Left posterior arm. 



Left poster olateral ray. In the Comasterida? (see Orientation 3). 



Ligament pit. The (usually) well-marked pit or depression situated in the dorsal 

 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 Comasterida? the circurnoral ring is more or less differentiated into a 

 smaller anterior and a larger posterior portion 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. 



