MONTGOMERY: GORDIACEA. 41 
Apparently neither hairs nor spicules occur in the vicinity of the lobes. At 
the anterior point of union of the tail lobes, on the ventral surface of the body, 
is situated a V-shaped ridge, each arm of which is placed on the ventro-median 
margin of the corresponding tail lobe, the two arms of the V converging, and 
joining at an angle cephalad at the anterior point of union of the tail lobes. 
Anterior to this ridge is situated a broad and deep depression. At the deepest 
part of this depression, i, e. in the medio-ventral line just anterior to the ridge 
described, is situated the cloacal aperture; this aperture lies on the summit of 
a slightly elevated papilla. ‘The anterior margin of the depression which sur- 
rounds the cloacal papilla forms a sharp ledge, irregularly semicircular in out- 
line (the opening of the semicircle directed caudad); this sharp ledge, forming 
the anterior and lateral margin of the cloacal depression, is not elevated above 
the level of that portion of the ventral surface of the body which lies anterior 
to the depression. Along this ledge are arranged a row of short, thick hairs. 
Accordingly, we find on the ventral surface of the posterior end of the male a 
narrow V-shaped ridge at the base of the tail lobes; anterior to this a large and 
deep depression, in the centre of the posterior part of which the cloacal papilla 
is situated; and the anterior and lateral boundary of this depression, formed by 
a nearly semicircular sharp ledge. 
Cuticle. There are no areoles, but a system of broad intersecting, oblique 
lines, between which are much finer intersecting lines. Short hairs also occur 
here and there, but sparsely. The cuticle is thus very similar to that of G. 
aquaticus robustus (Leidy). 
Color. Body of a dull olive-brown color. Tip of the head yellowish white, 
the remainder of the head reddish brown, varying in shade. The posterior end 
of the female is yellowish ; the pit in which the clpacal aperture lies is of a 
deep reddish brown color, there being thus a disk of this color immediately 
around the aperture. Inthe male the postcloacal cuticular ridge is reddish 
brown, its posterior edge black, 
Dimensions. Length of female, 470 mm.; greatest diameter, 1.8 mm. 
Length of largest male, 340 mm. ; greatest diameter, 1,3 mm. 
Especial Diagnostic Characters. The presence of a posteloacal ridge in the 
male, and the presence of a sharp precloacal ledge which bounds the cloacal 
depression; the intersecting lines of the cuticle. 
Comparison. These specimens seem to agree wholly with Camerano’s 
description of the species. This form is most closely allied to G. aquaticus 
robustus (Leidy). 
Geographical Distribution. Asuncion, Paraguay; Palmeira (Parana); Casa- 
bianca, Chile. 
