1. Those species of Proteocephalid Cestodes in which the testes are situated in the cortex may be described as of the Monticellia type. Of this type there are three conditions : (a) the Monticellia condition in which the testes, uterus, ovary, and vitellaria are all situated in the cortex; (b) the Rudolphiella condition in which the testes and vitellaria alone are in the cortex, the other organs being entirely or almost entirely in the medulla ; and (c) the Marsypocephalus condition in which the testes alone are in the cortex, all other organs being medullary.
Fuhrmann's genus Goezeella is synonymous with Monticellia if we ignore the characters of the scolex as features of generic value.
2. The anatomy of two species of Marsypocephalus is described: Marsypocephalus rectangulus Wedl, 1862, and Marsypocephalus heterobranchus, n.sp., from Nile Siluroid fishes.
3. It is concluded that the cortical situation of the testes and other organs is a taxonomic feature of generic value only (as in Pseudophyllidea in the case of the vitellaria) and La Rue's new family of the Monticellidae, created to include Monticellia-like forms, is not accepted. Monticellia, Rudolphiella, and Marsypocephalus are thus regarded as new genera in the Proteocephalidae.
4. The facts that the ‘Corallobothrium’ type of scolex is found in all of the three genera Monticellia (as amended by me and including ‘Goezeella’ siluri, Fuhrmann), Rudolphiella, and Proteocephalus (as amended by me and including ‘Corallobothrium’ solidum, Fritsch), and that in the Caryophyllaeidae, Bothriocephalidae, and Cyclophyllidea (cf. e.g. Taenia solium and Taenia saginata) minor scolex characters are evidently only features of specific value, compel us to delete such genera as Corallobothrium, Choanoscolex, Acanthotaenia, and my own recent genus Gangesia and to regard them as synonyms of Proteocephalus (La Rue's genus ‘Ophiotaenia’, syn. ‘Crepidobothrium’, not being accepted). Fuhrmann's Goezeella siluri becomes Monticellia siluri, and Fritach's Corallobothrium solidum becomes Proteocephalus solidus. The genera of the Proteocephalidae are thus four in number: Proteocephalus , Monticellia, Rudolphiella , and Marsypocep, halus, and these are formally or informally redefined. The two species of Marsypocephalus are diagnosed.
5. The ‘Taenia malopteruri’ of Fritsch, 1886, is not of the Monticellia type, as suggested by La Rue. Its structure is of the usual Proteocephalid type, save that the scolex possesses a rostellum and a broad band of hooklets and is covered with spinelets. It is renamed Proteocephalus malopteruri.
6. A new species of Clestobothrium--Clestobothrium clarias, from Clarias anguillaris Günth-is described. It is of interest, not only as being the third (second ?) species known of the genus, but because it affords one more illustration of the fact that the characters of the scolex cannot be used for diagnoses of genera. For this reason also, Lönnberg's genus Ptychobothrium (1889) becomes synonymous with Diesing's genus Polyonchobothrium (1884).
Labiobaetis Novikova & Kluge in West Africa (Ephemeroptera, Baetidae), with description of a new species