Revision of the subgenus Neopsacas (Hexactinellida, Rossellidae, Crateromorpha) with the description of new species and subspecies

Discovery of new specimens of Crateromorpha (Neopsacas), which are attributed to new species, from the Pacific, Antarctic and Indian Oceans and the description of new specimen also from the Atlantic Ocean allow us to review the skeletal characters regarding the dermal-hypodermal-atrial-hypoatrial spicule composition in various species of subgenus C. (Neopsacas). A new diagnosis of this taxon is proposed, and several new species and subspecies described: Crateromorpha (Neopsacas) krinovi krinovi sp. nov., ssp. nov., Crateromorpha (Neopsacas) krinovi discoli ssp. nov. and Crateromorpha (Neopsacas) obi sp. nov. The status of the subgenus Neopsacas within the Rossellidae and its close relation to Caulophacus are now well established according to morphological characters. The distribution of this subgenus is wide: Atlantic, Pacific, Indian and Antarctic Oceans. Possible phylogenetic affinities between the genera Crateromorpha and Caulophacus are discussed.