NO, 3 DEICHMANN: HOLOTHURIOIDEA ; PART I, DENDROCHIROTA 139 



As this discontinued distribution seems at most unbelievable, it is for 

 the present assumed that the labeling is erroneous. The record is given 

 here in case future investigation should prove that it is correct and a 

 species closely related to T. nutriens, or identical with it, does occur in 

 the waters around Galapagos Islands. Comparison with material from 

 California has failed to reveal any tangible differences in the spicules. 



The living animal (observed in Hopkins Marine Station) is brilliant 

 red with a more pinkish sole. The inner anatomy is similar to that of 

 Psoltdiurn. The third mesentery is attached in the left ventral interambu- 

 lacrum, close to the midventral ambulacrum. The respiratory trees are 

 feebly branched and attached to the lateral interambulacra; the muscula- 

 ture is moderately developed, the retractors short and attached near the 

 oral end. The genital organs form short tubes in 2 tufts near the oral 

 end ; they open on a papilla immediately behind the tentacles ; small gen- 

 ital organs are present in specimens 0.6 mm. long. The eggs are huge, 

 about 1 mm. in diameter, and reddish gray, opaque. The eggs are trans- 

 ferred to the back of the female and lodged in pits; about 10 eggs are 

 hatched at a time; when ready to leave the mother in a few weeks, the 

 young are pale rose colored and have their full number of tentacles and 6 

 large tube feet. Specimens 2 mm. long have developed a distinct sole; 

 those 5 mm. long have 3 rows of feet on the ventral sole. In Monterey 

 Bay the female has been observed brooding its eggs from March to No- 

 vember; very likely it broods during the remaining winter months also. 



2. Thyonepsolus beebei Deichmann 

 Plate 28, Figs. 1-3 



Thyonepsolus beebei Deichmann, 1937, p. 172, text figure 3, 1-10; 1938, 

 p. 382. 



Diagnosis. — Small form (length of sole few cm.). Exterior typical of 

 the genus ; dorsal side completely covered by scales. Ventral sole with 

 flat plates with scalloped edge ; dorsal side with large complicated lacelike 

 hourglass-shaped bodies, towers and curved perforated plates; tube feet 

 with end plate and curved plates with 4 central holes and numerous mar- 

 ginal ones. Tentacles with heavy rods in stem ; branches with delicate rods 

 and rosettes. 



Type.— M.C.Z. 



Type locality. — Off Arena Bank, L. Calif., 2.5 fms. 



Distribution. — West coast of Lower Calif., Mex., Costa Rica, pos- 

 sibly also Panama ( ?Lissothuria ornata Verrill, 1867, p. 322). 



