description of some new marine Planariee. One of these,which he has named P. [?] oceanica, is characterized by twoear-like processes, situate upon the neck-shaped anteriorextremity of the body. Planaria formosa, another marinePlanaria, has no exsertile mouth-sucker, but four groups ofocelli on the anterior part of the back, and is characterizedby red, purple, and white markings. A third species hasbeen named by Darwin Planaria [?] macrostoma, theanterior extremity of the body is square, truncate, and canbe employed as a suctorial acetabulum. On its neck aretwo large black ocellar spots, whilst the alimentary orifice,with an extremely long mouth-sucker, is situated in the pos-terior half of the body. A fourth species, Planaria [?]incisa, presents a sinuous-toothed, anteriorly deeplyindented, margin, which at the anterior edge supports verynumerous crowded ocelli. In the median line of the abdo-minal surface four apertures are placed, one behind theother, of which the penultimate is an oral orifice, from whicha thin, much folded, sinuated mouth-sucker can be pro-truded, and which, when extended, is quite as wide as thebody. On a fifth species Darwin has founded the new genusDiplanaria, which is characterized by a double alimentaryorifice, with two exsertile mouth-suckers, and behind whichtwo genital orifices are placed. Its ocelli are collected intofour groups. The only species, Diplanaria notabilis, occursunder stones [in tidal pools], but also swims freely in thesea water by the movements of its toothed foot-border.
Sipunculus capitatus has been described as new byRathke (Nov. Act. Natur. Curios, t. xx, P. i, 1843, p. 143.)The animal has a thick cephalic extremity, with a long con-stricted neck, and the oral orifice is furnished with aboutfifteen flattened, lanceolate tentacles. The middle portion ofthe body is surrounded with a belt of minute blackish