3V6 Verrill, Notes on Radiata. 



Supplementary Note on Echinoderms of the West Coast of America. 



OpMura variegata Lyman (see p. 254), and Ophiolepis variegata Lutken (see p. 256). 



Numerous large and fine specimens of these two species, with a few of Ophiocnida 

 hispida Lyman, were dredged by Mr. Bradley on a shell-bank in 4-6 fiitlioms of water, 

 Panama Bay. 



OpMothela mirdbilis Verrill (see page 268). 



Numerous additional specimens of this species, some of them much larger than those 

 first described, have been found clinging to Gorgonim and MiiriceoB from Panama Bay. 

 Also on Muricea from Cape St. Lucas. These confirm its rank as a distinct genus. 



Echinometra rupicola A. Ag. (see page 308). 



Several fine specimens of this species were obtained by Prof B. Silliman near San 

 Juan del Sur, Nicaragua, where they burrow in a hard argillaceous rock, forming 

 cavities sometimes 5 or 6 inches in diameter. 



Pattalus Peruvianus Verrill, = Anaperus Per nanus, p. 322 (non Troschel). 



The large specimens referred to, from Callao, when dissected proved to be a species 

 allied to P. mollis Sel., the only known species of the genus, from Chili and Peru. 



It has 20 long arborescent tentacles, some of which are shorter. The oral ring con- 

 sists of ten loosely articulated, long plates ; five slender ones, having the posterior 

 part broad triangular, with the angles rounded and edges concave, connecting anteri- 

 orly by a narrow middle with a long fusiform process, alternating with, five much larger 

 ones, having a short posterior portion, emarginate behind, narrowing somewhat ante- 

 riorly, and then expanding into a broad deeply excavated portion, ending in two points 

 anteriorly. The large plates in a large specimen are '7 of an inch long, -25 broad. Polian 

 vesicles long and slender, numerous, in large clusters. Color uniform deep crimson 

 when Uving. The tentacles are 4-6 inches across in expansion. In alcohol deep 

 purple. Anal orifice round, unarmed. 



This is, probably, the Holothuria Peruviana Lesson. P. mollis Sel.,* as figured, dif- 

 fers in its smaller oral plates and fewer Polian vesicles. 



EXPLANATION OF PLATE IV. 



Figure 1. ^^\q\A& o? Hymenogorgia quercifolia'K&w.; \-a, double-spmdles; lb, cres- 

 cent-'shaped spicula, — enlarged 150 diameters. 



Figure 2. Spicula of Pterogorgia gracilis Verrill ; 2a, double-spinldes ; 2b, cres- 

 cents, — enlarged 150 diameters. 



Figure 3. A part of a branch of the same, — natural size. 



Fio-ure 4. Spicula of Eunicea humilis Edw. ; a, spindles from coenenchyma, — en- 

 larged 50 diameters; b, club-shaped spicula,— enlarged 100 diameters. 



Figure 5. Spicula of Ple.vaurella dichotoma K611. ; 5a, a cross-shaped spiculum with 

 unequal branches ; 5b, a cross with two of the branches undeveloped, — enlarged 100 

 diameters. 



Pio-ure 6. Cross-shaped spicula of Plexaurella anceps f Koll. ; 6a, one of the larger 

 spindles, — enlarged 100 diameters. 



Fio-ure 7. Echinaster crassispina VerriU ; part of ray, — natural size. 



Fio-ure 8. Thyone Braziliensis VerriU ; a, oral plates, — natural size. 



Fio-ure 9. Chriodota rotiferiim Stimp. ; calcareous wheels of the skin, — enlarged 

 150 diameters. 



Figure 10. Amphiaster insignis Vernll; ray and part of disk, — natural size. 



* Zeitschrift fur Wissensch. Zool., Dec. 1867, p. 113, Taf. VIII, Fig. 4-5. 



