6 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 122 



trees flattened tubes with long simple branches. Ventral retractor 

 muscles smaller than dorsal muscles (perhaps an artifact of preserva- 

 tion). Calcareous ring simple, interradial pieces bluntly pointed 

 anteriorly, radial pieces notched anteriorly for attachment of radial 

 muscles. Posterior margin of calcareous ring undulating, lacking 

 projections. 



In smaller specimens towers not nearly as well developed as in holo- 

 type (fig. 2k) ; deposits in sole tend to have a more regularly indented 

 margin (fig. 2f). 



Remarks. — Lissothuria beebei (Deichmann) is regarded here as a 

 synonym of L. ornata. No significant differences between these 

 species can be found; in her original description of L. beebei, Deichmann 

 (1937, p. 174) called attention to the possibility that the species were 

 synonymous (see above). L. ornata may be distinguished readily 

 from other Eastern Pacific species since it is the only species that 

 possesses rosettes in the tentacles. 



Distribution. — The species has been recorded from the following 

 locaUties: Pearl Island, Gulf of Panama (type-locahty; Verrill, 

 1867, p. 322); Taboga, Panama, coast under stones at low water, 

 collected by Th. Mortensen, Nov. 7, 1915; off Arena Bank, 23°26' N, 

 109°24'30" W, 2.5 fathoms, in Pocillopora ligulata (type-locahty of 

 L. beebei; Deichmann, 1937, p. 173); Tangola-Tangola, Mexico, 

 15°46' N, 96*'06' W, 15-20 fathoms (Deichmann, 1941, p. 140); 

 Thurloe Bay, west coast of Lower Cahfornia, 8-10 fathoms (Deich- 

 mann, 1941, p. 140); Situatanejo Bay, Mexico, 17°37' N, 101°34' 

 W, shore (Deichmann, 1938, p. 382) ; Jasper Island, Gulf of Nicoya, 

 Costa Rica, 9°46' N, 84°54' W, shore (Deichmann, 1938, p. 382). 

 The species thus ranges from Lower California to Panama in depths 

 of 0-36 meters and has been found on two occasions in association 

 with corals. 



Lissothuria nutriens (Clark) 



Thyonepsolus nutriens H. L. Clark, 1901a, p. 169, figs. 6-14; 1901b, p. 491; 1923, 

 p. 161.— Deichmann, 1937, p. 174; 1941, p. 138, pi. 26 (figs. 1-5). 



Diagnosis. — Dorsal scale covering incomplete. Deposits of dorsal 

 surface are towers and hourglass-shaped deposits; no cups. Deposits 

 of sole are perforated plates with raised marginal projections and 

 small cups. Tentacles lack rosettes. 



Material examined. — Allan Hancock Foundation: Velero Sta. 

 1447-42, Point ArgueUo Boat Station, outside of breakwater, among 

 loose rock in tide pools, collected Mar. 13, 1942, by F. C. Ziesenhenne, 

 I specimen; Velero Sta. 1575-46, 6.7 miles south of surf, Pedernales 

 Pomt, Santa Barbara Co., Calif., intertidal, Dec. 7, 1946, 1 specmien; 

 Velero Sta. 1576-46, 0.5 mile north of Cayucos, San Luis Obispo Co., 

 Calif., intertidal, Dec. 8, 1946, 1 specimen. 



