NO. 3 DEICHMANN : HOLOTHURIOIDEA ; PART I, DENDROCHIROTA 145 



3. Psolidium ekmani, new species 

 Plate 30, Fig. 6 



Diagnosis. — Small form (length of sole about 1 cm.). Oral and anal 

 openings closed by indistinct valves ; stout radial teeth present inside the 

 oral plates; about 5 scales between the oral and anal valves. Scales 

 strongly sculptured with several pearllike projections, firmly attached; 

 dorsal tube feet few. Sole with rows of marginal feet and a row of few 

 feet scattered along the midventral ambulacrum. Spicules in sole delicate 

 4-holed buttons and plates with a larger number of holes ; a varying num- 

 ber of knobs are present on the surface. Feet with end plate and support- 

 ing rods. Dorsal side with no other spicules than the scales ( ?). 



Type. — Holotype, AHF no. 39, 1 paratype. 



Type locality.— Station 213-34, La Plata Island, Ecuador, 7-10 fms., 

 dredging north of anchorage, Februaiy 10, 1934. 



Distribution. — From Ecuador to Panama. 



Depth. — From 7-10 fms. 



Specimens examined. — The type and one other specimen from the 

 following Hancock stations : 

 213-34. La Plata Island, Ecuador, 7-10 fms., February 10, 1934, 1 



specimen. 

 863-38. Bahia Honda, Panama, off North Island, rock, mud, sand, 30- 

 50 fms., March 1, 1938, 1 specimen. 



Re/narks. — The species was at first assumed to represent Psolus pata- 

 goniciis Ekman, but comparison with the latter showed clearly that the 

 spicules were entirely different (plate 30, fig. 8). Neither could it be 

 referred to Psolus squamatus (Koren), var. segregatus Perrier because 

 the projections on the scales were not loose but part of the scales. Also the 

 presence of tube feet in the midventral ambulacrum separates it distinctly 

 from both species mentioned above. Finally a few tube feet were dis- 

 covered on the dorsal scales and the generic position thereby settled. The 

 species is named in honor of Dr. Sven Ekman, the well-known zoogeog- 

 rapher and student of holothurians, from Upsala, Sweden. 



4. Psolidium planum, new species 

 Plate 30, Figs. 1-5 



Diagnosis. — Small form (sole up to 1.5 cm. long), body capable of 

 becoming extremely flattened. Sole distinct; feet marginal and present as 

 a scattered row of much smaller appendages in the midventral ambu- 



