582 Verrill, Notes on RacUata. 



still smaller scattered tubercles. The miliary tubercles are rather 

 large and numerous, except along a central, narrow, naked band, which 

 commences at the periphery and becomes depressed and conspicuous, 

 but not wider, toward the summit. In the arabulacral zones the 

 primary tubercles border the poriferous zones throughout ; the in- 

 terior secondary rows are represented toward the summit by small 

 tubercles scarcely distinct from the miliaries, but become regular 

 toward the periphery, where the tubercles are nearly as large as the 

 primaries, but they fade out before reaching the actinal areas ; at and 

 below the periphery there are small tubercles scattered in the central 

 region, but on the upper side there is a very nai-row naked band. 

 The pores are rather large, forming conspicuous zones above, which 

 become much narrower below. On the lower side the pores are in 

 regular oblique rows of three pairs, but above they appear to form 

 a regular inner vertical row, separated by a row of small tubercles 

 from the two, less regular, alternating, outer rows. The genital 

 plates are thick, with the outer end obtusely rounded, and sunken 

 around the large, round genital orifices. The anal membrane is 

 covered with numerous irregular, separated plates, forming about 

 three irregular outer circles and a central radiating group of smaller 

 ones. The jaw supports are stout and elongated, narrowed toward 

 the end, with an elongated, elliptical foramen. The few larger spines 

 that remain on the upper surface are short, stout, and blunt. 



The color of the test is yellowish beneath, this color extending up 

 into the central parts of the arabulacral and interambulacral zones 

 above ; the rest of the upper side is brownish, with more or less red, 

 especially on the naked bands; spines pale brown. 



This species differs from B. rosea in its much thicker test, less de- 

 pressed form, more prominent ambulacra, much more numerous and 

 larger tubercles, narrower naked bands, less acute genital plates, 

 different anal ai-ea, etc. 



The specimens formerly described by me as P. pictus appear to be 

 the young of this species. Before the large specimen above described 

 was known, a comparison of those with authentic specimens of L. semi- 

 tnberculatus had convinced both Mr. Agassiz and myself that they are 

 really quite distinct from the latter. 



L. seinituherculatus (Val. sp.) Verrill (p. 333) differs from B. picta, 

 young, in having fewer and more distant tubercles, and broad, well- 

 defined, naked areas, bearing only small granule-like miliaries in the 

 interambulacral zones of the upper side, instead of the very small 

 and narrow naked areas, encroached upon by the numerous, crowded 



