1869.] 383 [Verrill. 



ambulacrum the bend of the fascicle extends inward only one sixth 

 of the length of the posterior ambulacral furrows, and in the lateral 

 interambulacra it extends inward less than half the length, and then 

 forming an obtuse angle, passes obliquely downward and across the 

 interambulacral region in a straight line, for nearly half an inch, to 

 another angle near the margin of the anterior lateral ambulacra, 

 fr.om whence it passes outward for .1 of an inch, diverging a little 

 from the furrow, to another angle where it joins the lateral fasciole. 

 From this angle it approaches the furrow again in a slightly curved 

 line, passing around and close to its end. In the anterior lateral 

 interambulacra it forms but one broad round angle, at about three 

 tenths the distance between the end of the anterior lateral furrows 

 and the centre. The lateral fasciole is somewhat sinuous, passing 

 under the anal area in a broad curve. Anal area broad, elliptical, 

 liigher than broad, situated toward the upper part of the truncated 

 posterior end, its plane nearly perpendicular to the lower surface. 

 Plastron broad shield-shaped, only slightly narrowed behind. 



Length 2.10; breadth 1.95; height 1.45; from apex to anterior 

 margin, in ambulacral furrow, 1.10; apex to posterior margin, at anal 

 area, 1.70; apex to end of anterior lateral ambulacral furrows .1; to 

 end of posterior lateral .95; apex to inner angle of the fasciole in the 

 anterior interambulacra .70; to inner angle in latei'al interambulacra 

 .55; to same in posterior interambulacrum .73; breadth of anal area 

 .24; height .36; length of plastron 1.55; breadth .95. 



Locality unknown. 



This species agrees well with D. australis Gray, the type of the 

 genus, but shows good specific differences in its more angulated form, 

 more emarginate anteriorly; in its less eccentric apex; in its broader 

 plastron, much less narrowed posteriorly; in its more squarely trun- 

 cate and less oblique posterior, and larger and less ventral position of 

 the anal area; and especially in the form of the peripetalous fasciole, 

 which does not extend nearly so far toward the centre in the interam- 

 bulacral regions. 



Mellita longifissa Michelin. 



Since the publication of my ' ' Notes on the Echinoderms of Pan- 

 ama and West Coast of America," I have seen quite a number of 

 specimens of this species, which was then unknown to me. These 

 are from La Paz, Capt. Pedersen; Gulf of California, Robt. E. C. 

 Stearns; Acajutla (Corinto), McNiel. 



This species is the Pacific analogue of M. pentapora of the Atlantic 



