132 Macteay Memortat Vouvume. 
XV.—Systematic Account oF THE GENERA AND SPECIES. 
Family TEMNOCEPHALE. 
In order to include the new genus Crasfedella it will be necessary to alter still 
further Braun’s modification* of my original diagnosis of the family. 
Monogenetic Trematodes (?) with dorsi-ventrally compressed body provided in 
front with four to twelve long, slender tentacles. No anterior sucker, but a large 
posterior one, devoid of hooks or marginal membrane and only exceptionally distinctly 
radiated. The integument consists of distinct cuticular and epidermal layers, with a 
basement-membrane. The epidermis is nucleated, but not divided into cells; in some 
cases it is ciliated. In most instances there is below the basement-membrane more 
or less pigment. Mouth situated some little distance behind the anterior end of the 
animal or the bases of the tentacles; a powerful spheroidal muscular pharynx in 
Temnocephala but not in Craspedella; the intestine unbranched, but in most of the 
species constricted at regular intervals by a series of imperfect septa. A pair of 
contractile excretory sacs with dorsal and anterior openings. yes usually, though 
not invariably, present. A single genital opening situated near the sucker; a genital 
cloaca into the cavity of which the protrusible cirrus projects and into which opens 
also the efferent duct of the uterus (here called vagina), which sometimes contains 
chitinous teeth. Ovary oval, elliptical, or spherical ; a large receptaculum seminis or 
receptaculum vitelli; vitelline glands consisting of numerous lobes extending over the 
dorsal and lateral walls of the intestine. Two pairs of compact testes ; a chitinous 
cirrus armed with spines at the extremity. Eggs with stalk-like appendages, by 
means of which they are sometimes attached ; dehiscing sometimes by the separating 
off of an operculum-like part of the egg-membrane. 
Genus TEMNOCEPHALA, Blanchard. 
A number (four to twelve) of slender tentacles confined to the anterior extremity 
of the body. A large muscular pharynx. No posterior fringes or papille. 
* Lic. p. 524. 
+ Lic. p. 299. 
