a1 Wellcome Bureau of Scientific Research, Endsleigh Gardens, London, N.W. 1.
1. A new species of Bothriocephalus—B. pycnomerus—is described from the intestine of Ophiocephalus marulius Ham. Buch., from the Ganges and Jumna at Allahabad, India.
2. B. pycnomerus closely resembles B. histiophorus (Shipley 1901; from the marine sword-fish Histiophorus) in structure but differs chiefly in the possession of an armed scolex and its crowded indistinct segmentation.
3. Lühe's definition of the genus Bothriocephalus must be amended to include forms with armed scolices and forms in which the ventral uterine apertures are a-median and irregularly alternate.
4. Two new species of Proteocephalidae are described which possess armed muscular rostella, and for these a new genus Gangesia is created and defined. The definitions of the Order Tetraphyllidea (Lühe 1910) and of the Family Proteocephalidae (La Rue 1914) must be amended to include forms possessing muscular rostella, armed or unarmed.
5. These two new species—Gangesia wallago and G. macrones—were found in the intestines of Wallago attu Bleek and Macrones seenghala Sykes (both Siluroids) respectively, from the Ganges and Jumna at Allahabad.
6. Southwell's “Ophryocotyle bengalensis,” from Ophiocephalus striatus, Labeo rohita and Wallago attu, is probably identical with Gangesia wallago.
(Received October 04 1924)