28 BULLETIN 93, UNITED STATES NATIONAL MUSEUM. 



The cirri in the individual figured and another of the same lot a,re 

 extremely slender and long, as in typical V. alba. Cirrus i of 10 and 

 21 joints, the shorter ramus about one-third as long as the longer. 

 Cirrus ii is similar, with 8 and 18, or 9 and 21, joints. In cirrus iii 

 the shorter ramus is over three-fourths as long as the longer, thus 

 approaching the condition of the posterior cirri. Terminal appendage 

 has 22 long joints, is about three times the length of the protopod, 

 and from over one-half to nearly two-thirds as long as cirrus vi. 

 The penis is nearly twice as long as the protopod, being 1.2 to 1.7 

 mm. long. The mandible (fig. 76) has three teeth, and seven or 

 eight points on the lower angle, the upper tooth being very large 

 and widely separated from the second. The maxilla (fig. 7 a) has, 

 below the upper great spines, a deep recess in which a group of short 

 spines stands. The projecting lower edge has large and small spines 

 mingled. 



VERRUCA ALBA CARIBBEA, new subspecies. 

 Plate 2, fig. 4. 



Type. Museum of Comparative Zoology. 



Type-locality. Off Grenada, West Indies, in 92 fathoms, on a spine 

 of Dorocidaris affinis (Philippi), Blake expedition. Also off Guada- 

 lupe in 150 fathoms, on spine of D. affinis, Blake expedition. 



Twenty-three individuals on one spine of Dorocidaris are, with the 

 exception of a few young specimens, of nearly uniform size. In 

 sixteen of the lot the right scutum and tergum are movable. Some- 

 times the first articular ridge of the scutum is very weak and there is 

 variation in the articulation of the carina and rostrum. As a rule 

 each has three ribs and teeth. In a few examples the second rib and 

 tooth of the carina are much broader than in others. The upper rib 

 of the carina is always quite narrow, and the short ribs terminating 

 on the tergal margin are either extremely small, never more than two 

 in number, or, in a majority of the specimens, they are absent or barely 

 perceptible. The basal edge of the wall is as obtuse as in the type 

 form in some examples, thinner in others. 



Greatest carinorostral length 4.1, height of fixed tergum 2 mm. 



Cirri are as in typical V. alba. The teeth of the mandible are 

 more slender. 



Three individuals from off Guadalupe in 150 fathoms, Blake col- 

 lection, are similar, but larger, the largest 4.8 mm. long. 



VERRUCA ALBA BARBADENSIS, new subspecies. 

 Plate 2, figs. 3, 3a. 



Type. Museum of Comparative Zoology. 



Type-locality. Off Barbados in 106 fathoms, on the spine of Doro- 

 cidaris bariletti A. Agassiz, Blake expedition. 



The shape is more depressed than V. alba. The tergal area of the 

 movable scutum is narrower, its ribs three or four in number are 



