466 PROF. W. A, HASWELL ON AUSTEALASIAN POLYCLADS. 



of the Australian Museum, Sydney, and Prof. W. B. Benliani,of Dunedin, N.Z., by both 

 of whom I was given the opportunity of examining specimens from the collections under 

 their charge, to Mr. Chas. Hedley for specimens collected at Masthead Island and 

 Cooktown, and to Mr. S. J. Johnston, P. A., B.Sc, Senior Demonstrator of Biology, 

 Sydney University, for the specimens of Liplosolenia. 



The most important morphological and physiological results embodied in the following 

 ai-e : — (1) the discovery of a new Planocerid (named Trifylocelis) with three reproductive 

 apertures ; (2) the discovery of a Cryptocelis-\\k.Q, form with a genito-intestinal canal ; 

 (3) the evidence of a peculiar mode of coptilation by localized perforation in the new 

 Australian genus Echinoplana. 



The nomenclature of the parts of the female reproductive apparatus of the Polyclads 

 is somewhat confused, and, without any intention of dogmatizing as to homologies, it is 

 necessary that I should state here the terms used in the following descriptions, and the 

 sense in which they are employed. The term ovaries needs no comment. The oviducts 

 are the ducts by which the ova reach the uteri. The uteri are the two elongated chambers 

 in which the fully-developed ova collect, and in which they undergo maturation and may 

 become fertilized. The ducts by wliicli the ova pass out from the uteri are the uterine 

 ducts ; verv commonly the right and left uterine dacts unite to form a median uterine 

 duct. The remainder of the apparatus consists of a median passage to the whole of which 

 I apply the term vagina. The part of this into which tlie female aperture directly leads 

 is the antrum femininum. This, or a part of it, may have its walls thickened to form a 

 Ijursa copulatrix. The part following on this is the ootype ; this is the region into which 

 the ducts of the shell-glands open. The ootype usually runs upwards and forwards, or 

 directly upwards, and bends sharply back to pass into the dorsal limb of the vagina, 

 the shell-gland ducts being frequently continued on this for some distance, and even on 

 the terminal portions of the uterine ducts. Into the dorsal limb of the vagina open the 

 uterine ducts, or median duct, as the case may be. Beyond this point the vagina may be 

 ])rolonged backwards. Sometimes it terminates in a median sac, the receptaculum 

 scminis; rarely there are two receptacula, right and left. In a few cases the vagina 

 terminates behind by opening on the ventral surface of the body by a posterior female 

 aperture. 



Tripylocelis typica, n. g., n. sp. (Plate 35.) 



In the living condition this Polyclad is about I'o to 2 cm. in length, and in breadth 

 aljout 0'75 to 1 cm. — the breadth not being more than half the length. The brain, 

 tentacles, and eyes are in the first fifth. The mouth is in front of the middle. The 

 male aperture is in the last third. Tiie space between the male and female apertures 

 is about one-half of that between the latter and the posterior margin. 



The tentacles are in the form of elongated cones ; they are not retractile into de- 

 pressions at their bases. The arrangement of the eyes (PI. 35. fig. 2) is fairly constant. 

 Each tentacular group comprises some twelve to twenty. Two or three small eyes are 

 usually to be detected in the tentacles above the level of the others. Of the remainder 

 there are rarely any situated directly over the brain ; but they all, or nearly all, lie in 



