96 NILS HJ. ODHNER, MOLLUSCA. 
»Schleimdräse>», and give no other expression of opinion about his investigations on these 
organs than the following words (p. 112): »SIMROTH hat diese Driäse auch gesehen, doch 
wurden von ihm die Mantelorgane nicht richtig erkannt». By such circumstances a 
future investigation must be awaited before complete certainty as to the organization 
of the genus Atopos is attained, as well as, basing thereon, an idea of its affinities 
is possible to gain. With respect to the relations within the genus, the present 
species differs from the forms described by SIMROTH in having a broader hyponotum 
and in the structure of its genital organs; further the retractor penis inserts rather 
far behind the retractor of the right body side. A muscular knot like that of A. 
semperi (cf. SIMROTH, 1891, fig. 19 a) is present on the bottom of the body cavity 
behind the mouth. "The differences named are not more important than that they 
justify at the most the establishment for this and the nearest allied forms of a distinct 
subgenus, Prisma, proposed by SIMROTH (1891). 
A parasitie nematod was found in the rectum of the present species. It will 
be described by Dr. DITLEVSEN, who has preliminarily named it Atopoeca intestinalis. 
FAM. LIMNAEIDAE. 
Isodora gibbosa GouLnp, var. brevispira n. Atherton (Jan. 1913), in a brook, 
many sps., max. h. 12.5; ap. h. 9 mm; whorls 5. On account of the gibbosity of 
the last whorl, which is most swollen above the middle, I have referred these spe- 
cimens to I. gibbosa; but they differ from the typical form (figured by E. A. SMITH 
1883, pl. 6 fig. 4) in a smaller (both narrower and shorter) spire. The colour is 
horny brown. The shape of the aperture, which is widened below and obtusely 
angled above, is typical. 
FAM. PALUDINIDAFE. 
Larina strangei A. ApaAms. Cedar Creek (March 1913), 4 sps, max. h. 4.4 mm. 
FAM. UNIONIDAE. 
Diplodon shuttleworthii LrzaAa (= Unio angasi SowEerBY). Coleman River, N. 
Queensland (Sept. 1913), one large shell, 1. 90 mm, and three smaller ones. The 
former agrees very well with fig. 282 in REEVE (Conch. Icon. 16) and with the 
description given by E. A. SmrITH (1883) of the livid lustre of its nacre, which reminds 
one of the interior of a Haliotis; the small shells, max. 1. 19 mm, have the posterior 
laterals simple in both valves, which may perhaps be a characteristic of a young 
specimen. 
FAM. CYRENIDAE. 
Cyrena ceylanica CHEMNITZ. Queensland, without definite locality, 1 sh., 1. 
82 mm. 
