NO. 3 deichmann: holothurioidea; parti, dendrochirota 63 



Panamic region. Particularly do I wish to thank Dr. Irene McCulloch 

 for her unflagging interest in this paper and for the amount of her own 

 valuable time which she unstintingly has given whenever I worked in 

 Los Angeles. 



Composition of the Fauna 



From the Panamic region 15 species of Dendrochirota, valid and 

 dubious, were described up to 1936; during the following years 6 new 

 species were added, thus bringing the total number up to 21. 



The present monograph treats 43 species which are valid and 3 which 

 are so poorly described that they must be completely rejected, unless the 

 types should be rediscovered. Three of the 43 valid species are probably 

 extraterritorial — Pachythyone rubra (H. L. Clark) and Thyonepsolus 

 nutriens H. L. Clark, not known with certainty south of Santa Cruz 

 Island, southern California, and Psolus patagonicus Ekman from the 

 Cape Horn region. All the valid species have been examined ; of these, 34 

 are represented in the Allan Hancock Foundation collections, while the 

 remaining 9 have been studied in the M.C.Z. and in the U.S.N.M. ; in 

 five cases the types have been available. Of the 34 species in the Hancock 

 collections 16 are new, while the 17th new species came from the collec- 

 tions of the Stranger^ which are deposited in the M.C.Z. 



List of Dendrochirota from the Panamic Region, Including a 

 Few from the Adjacent Northern and Southern WATERsf 



Cucumaria californica Semper p. 79 Leptopentacta nina, new species p. 97 



Cucumaria chilensis Ludwig p. 80 Pentacta peruana (Semper) p. 99 



Cucumaria dubiosa Semper p. 81 Thyonacta mexicana, new species p. 101 



Cucumaria crax, new species p. 83 Thyone neofusus, new species p. 104 



Cucumaria godeffroyi Semper (0)* p. 83 Thyone bidentata, new species p. 105 



Pentamera zacae Deichmann (0) p. 85 Thyone parafusus, new species p. 106 



Pentamera beebei Deichmann (0) p. 86 Thyone strangeri, new species p. 107 



Pentamera chierchia (Ludwig) p. 86 Neothyone gibber (Seienka) p. 109 



Pentamera chiloensis (Ludwig) p. 88 Neothyone panamensis (Ludwig) p. 112 



Pentamera panamensis Verrill (0)* p. 89 Neothyone gibbosa, new species p. 113 



Neopentamera anexigua, new genus, Pachythyone rubra (ILL. Clark) (0) p. 115 



new species p. 90 Pachythyone lugubris (Deichmann) p. 116 



Apentaraera lepra, new genus, new Pachythyone pseudolugubris, new 



species p. 92 species p. 116 



Leptopentacta nova, new species p. 95 Athyone glasselli (Deichmann) (0) p. 119 



Leptopentacta panaraica, new species p. 96 Anaperus peruviana (Lesson) (0)* p. 120 



t Dubious species are marked with an *; those not secured by the Allan 

 Hancock Expeditions are marked with (0). 



