SALENIA PATTERSONI. 13 



The abactinal system (PI. I\". Fig. 2), which is bul sparsely covered by 

 papillae, is remarkable for the size of the anal system, comparatively larger 

 than in the other species of the genus, and for the elongate genital and 

 ocular plates. 



The primary radioles are smooth, and uniformly tapering ; in one of the 

 specimens, which was of a light greenish pink color when alive, the spines 

 are white with a delicate brownish-pink base. In the other large specimen 

 they vary greatly in shape, from the peculiar serrated, short, flattened spines. 

 surrounding the actinostome, characteristic of this genus, to long, slender, 

 cylindrical spines, straight, or sometimes slightly curved, equalling in length 

 twice the diameter of the test, and finely tinted for the whole length, or 

 to the shorter radioles, gradually becoming thicker towards the tip, with 

 coarser tinting ; we also find some spines with slightly cupuliform tips, as in 

 Goniocidaris. The largest specimen measures fully 72 mm. in diameter. 



* Salenia Pattersoni A. A,;. 



Salenia Pattersoni ,V. Aa. Bull. M. C. Z., V., No. !>, Fig. 1, p. 187, PI. V., 1878. 

 Salenia Pattersoni A. Ac;. Bull. M. ('. Z., VIII.. X... -1, y. 72, 1880. 

 Off Havana, Caribbean, West [ndies. 



PL IV Figs. 3-28; PL V. ; PL VI. Figs. is-.'.:. 



This is the most exquisitely colored of the living Salenidae thus far known. 

 When alive the test is of a light cream-color. The shafts of the primary 

 spines are banded alternately with cream-color and brilliant vermilion, the 

 colors being nearly equally divided. This coloring at first glance gives to 

 this species very much the appearance of the Florida species of Coelopleurus. 

 The secondarv spines arc also cream-colored, separated at the base by dark 

 violet belts, extending from the apical to the actinal system along both the 

 median ambulacra! and interambulacral lines. Similar dark violet lines 

 separate the genital plates and the superanal plate from one another, the 

 dark lines of the median ambulacra and interambnlacra extending some dis- 

 tance into their corresponding genital and ocular plates. The primary spines 

 ate from three to four times in length the diameter of the test, and carry mi- 

 nute, sharp, irregular serrations ; these are frequently worn o(f. the radiole 

 then presenting a nearly smooth surface, slightly granular. These spines 

 are remarkably uniform in their appearance, differing merely in length, 

 and we do not find among them the great variation so characteristic of the 

 primary spines of .V. varispina, the only exceptions being the Porocidaris- 



