286 Macreay Memorrat Vouume. 
conoid, especially anteriorly, where it ends in a rounded head which is truncate at the 
mouth. There are ten cephalic sete arranged as usual, one of each of the submedian 
pairs being shorter, the others being about one-sixth as long as the head is wide. 
I could discover no papillz. The conoid cesophagus is anteriorly one-half, posteriorly 
three-fifths as wide as the neck, being only very slightly enlarged near the head ; its 
lining is not very distinctly to be seen. From the rather indistinct cardiac collum 
the intestine is at once three-fourths as wide as the body. The duct of the ventral 
gland ends in an ellipsoidal ampulla, and empties through a ventral pore at the 
commencement of the second fifth of the neck (3°67%). The lateral fields are one- 
fourth as wide as the body. The anterior half of the tail is concave-conoid, thence, 
however, it is uniformly one-fifteenth as wide as at the base. The three small 
elongated pyriform caudal glands lie just behind the anus. The ventral row of male 
accessory sexual organs is composed of seven fascicles equidistantly arranged, the 
posterior one being opposite the middle of the spicula and the whole row being 
considerably longer than the tail (14°/,). The elongated spicula are of nearly 
uniform size, being slightly arcuate in the proximal halves; their length is half as 
great again as that of the anal body-diameter. There are probably two testicles 
arranged symmetrically, 
FTab.—Mud of a brook, Sydney, New South Wales, Australia. 
Genus PRISMATOLAIMUS, de Man. 

1. P. intermedius, Biitschli (?). 7-5-3 
by about four hundred transverse striz. Minute and extremely inconspicuous hairs 
occur from place to place throughout the length of the body. The conoid neck 
terminates anteriorly in a truncate head, bearing near its margin six equal spreading 
setee, each about two-thirds as long as the head is wide. The lips are low and 
indistinct, but appear to be three in number; they bore no papille that I could see. 
Neither eyes nor lateral organs were to be seen. The edges of the triquetrous 
pharynx are indicated by three longitudinal ribs ; the main part is two-fifths as wide 
as the head and this is continued by a diminishing part through which it is connected 
with the cesophageal lumen. The cesophagus where it receives the pharynx is 
two-thirds as wide as the corresponding part of the neck; it soon diminishes however 
to one-half as wide as the neck, then gradually widens posteriorly until it becomes 
two-thirds as wide as the base of the neck. The granular intestine, which is two-fifths 
as wide as the body, is separated from the cesophagus by a deep, broad and very 
distinct constriction, opposite to which are two bodies whose function is unknown to 
me. I discovered nothing concerning the ventral gland, the longitudinal fields or 
20 
76°5 (7 D D 
© smm The cuticle is traversed 
