Genus Mesomyzostoma Remscheid, 1918
Myzostomatid with flattened, cylindrical or extremely branching lobate bodies; no cirri. Up to five chaetigers, parapodia very low, with small emergent hooks ventrally, distributed along body. Aciculae present, each with manubrium. Mouth at anterior tip of body. Cloaca (exit for digestive tract and uterus) at posterior tip of body. Body translucent or whitish or orange. Digestive diverticulae arising from central gut tube. Simultaneous hermaphrodites. One pair of male seminal vesicles opening at level of third pair of parapodia. No penes. Eggs filling dorsal side. Parasite of crinoid coelom.
Note: SAM, South Australian Museum; SIO-BIC, Benthic Invertebrate Collection, Scripps Institution of Oceanography.
New sequences in bold. Column a.k.a. refers to the alternative names previous used for the four new species described here in previous publications (Lanterbecq et al. 2006, 2009, 2010; Summers and Rouse 2014).
Mesomyzostoma was formerly in its own family, Mesomyzostomatidae, but is now regarded as part of Myzostomatidae (Summers and Rouse 2014).