x} NILS HJ. ODHNER 
described for A. hookeri. The same undivided appearance is met with in other 
forms of Stephanoda, e. g. S. livata Couthouy. There are no appendages of 
the mantle margin. 
More important differences are exhibited by the genital organs (fig. 11). 
These are in S. guadrata arranged and constructed thus: In the beginning of 
the third whorl the hermaphrodite gland is situated embedded in the superior 
lobe of the liver. It consists of two separate clusters each containing 5 (the 
upper) or 6 (the lower one) finger-like lobes. The thin hermaphrodite duct soon 
immediately widens to a long ampulla, with broad and irregular dilatations on 
its outer wall, then it narrows again, 
and runs towards the inside of the 
albuminiparous gland. Here a lengthened 
vesicula seminalis is attached which is 
embedded in the albuminiparous gland 
and only projects with its upper flexed 
end. The next portion of the herma- 
phrodite canal is rather wide, and intim- 
ately connected with the oviduct into 
which it soon debouches; no special 
prostata gland is developed. The oviduct 
is produced upward and downward; from 
its median portion the muscular vagina 
sets out and from its lower end the vas 
deferens takes its origin. At the point 
where the vagina begins a long-stalked 
spermatheca is attached; it extends 
along the oviduct upwards and is covered 
by this, only the apical end of the sperma- 
Fits Geniplorgnsof Stephanodaquadrefa theca projecting beyond the oviduct 
A hermaphrodite gland; o oviduct; ~ penis; Whereas the vagina is a simple 
2 Rae Pee i jenarulay Eetiaet Ore tube without any accessory equipment, 
ealaesehimalic. the male organ is somewhat unusually 
appointed. The vas deferens has the 
usual course beneath the retractor of the ommatophore, and then, after some 
coils, debouches into the apex of the greatly widened penis, near the insertion 
of its retractor muscle. Somewhat distally of this point, the penis is furnished 
with a thread-like winding appendix or flagellum, and a similar organ is attached 
far more distally, about halfway its length. 
Thus the genital organs are relatively simple, approaching the type of 
Pyramidula with respect to the long-stalked spermatheca, but there is a 
singular differentiation in the two appendices of the penis, features which have 
their nearest analogon in the genus Sagda from the Greater Antilles. I have 
found the same structure of the penis in another specimen of the genus, S. “ra/a 
Couth., from Lagotowia, Tierra del Fuego. 
The radula of the two Juan Fernandez Stephanoda species is helicoid, 
inasmuch as the teeth have squarish basal plates, and the marginals have three 
or more subequal cusps. As a common feature may be mentioned the smallness 

