PLATE 71. 

 Lepidesthes colletti White. Page 425. 



Fig. 1. Same specimen as photograph, Plate 69, fig. 1. X 3.4. A very completely preserved specimen, oriented by the 

 Loven method as the axes are known from the presence of the madreporite. Sixteen columns of ambulacral plates 

 at the mid-zone as seen best in area III. Ambulacral plates are all nearly or quite rhombic in form as are the younger 

 plates dorsally in very large specimens in which they are hexagonal at the mid-zone (Plate 69, fig. 7). There are but 

 few anlbulacral plates in a row in each area dorsally near the oculars, the number in the rows increasing passing 

 ventrally to the full number at or near the mid-zone. Four columns of plates in each interambulacral area, strongly 

 imbricating dorsally and from the center laterally and over the ambulacrals. In areas 1, 2, 3, and 5, column 3 has 

 the wider plates which imbricate laterally in two directions; but in area 4, column 4 has the wider plates. (See also 

 Plate 69, fig. 4; Plate 70, figs. 1 and 2.) Dorsally, four oculars are in place, which are indicated by cross lines; 

 adorally they cover the ambulacra and laterally the interambulacra in part on either side. Five genitals are in 

 place; genital 5 has three pores, genital 1 has two pores, and genital 2 shows fine madreporic pores, but no genital 

 pores; probably they are hidden under the adjacent plates, genitals 3 and 4 are partially hidden and do not show 

 any pores. Periproctal plates are thin, rounded, and rather scaly. This dorsal area is shown more enlarged in 

 text-fig. 251, p. 428 (pp. 34, 172, 174, 427, 428). 



Lepidesthes extremis sp. nov. Page 430. 



Fig. 2. Same specimen as photograph. Plate 72, fig. 1. Holotype. X 1.7. Internal siliceous mold of the ventral side 

 so that the ambulacral pores are on the lower part of each plate. (Compare Plate 67, figs. 15 and 16, where in Lepi- 

 desthes laevis the same ambulacral plates are seen in external and internal views.) There are sixteen columns of 

 plates in an ambulacral area near the mid-zone, as seen in areas B and H, but there are fewer columns of ambulacral 

 plates in an area farther ventrally. There are four columns of plates in the four interambulacra preserved, and 

 the same number is given in area E, which is restored as indicated by dotted lines. An impression of a powerful 

 lantern exists ventrally. Dorsal view of part of the same specimen, text-fig. 252, p. 431. 



