THE NATURAL HISTORY SURVEY. Ere 
Superfamily Agnathomorpha. 
Mouth provided with jaw; radula with aculeate teeth; 
mouth frequently developing finger-like appendages; cerebral 
ganglia concentrated, in close contact. 
FAMILY CIRCINARIID-. 
‘“‘Foot-edges with no trace of pedal grooves; no tail gland; 
sole undivided. Side teeth unicuspid, thorn shaped, with nar- 
row basal-plates. Shell with simple lip and without opaque 
markings.’’* 
Genus CIRCINARIA (Beck, 1837). Pilsbry. 
Macrocycls Beck, of Authors. 
Selenites Fischer, 1878 (non Hope). Haplotrema Anc. 
“Shell; Thin, widely umbilicated, depressed, striate or 
wrinkled, color uniform; whorls 4%-5, the last broad, de- 
pressed, moderately deflexed in front; aperture obliquely 
ovate; peristome somewhat thickened or expanded, the mar- 
gins approximating, the basal shortly reflexed.” 
“Animal: Heliciform; mantle posterior, covered with a 
shell; eye-peduncles long, slender; foot narrow, twice as long 
as the diameter of the shell, tail pointed, scarcely reaching 
behind the shell; respiratory and anal orifices on the right ot 
the mantle, under the peristome of the shell; generative orifice 
behind the right eye-peduncle; no distinct locomotive disk or 
caudal mucus pore. Carnivorous.” 
‘Jaw: Crescentic, ends sharply pointed, anterior surface 
striated; cutting margin smooth, with a median projection.’’** 
Radula: With numerous rows of teeth arranged en chev- 
von. For detail of the radula see concavus. 
“Genitalia: The epididymis is extremely long and very 
large, forming the peculiar feature of the system. The geni- 
tal bladder is oval, with along duct, which is very much broader 
at the end nearer the vagina. The penis sac is long, gradually 
tapering at its apex, where it receives the vas deferens. Upon 
the side of the vagina, about the middle of its length, is a wart- 
like protuberance, which may be a dart-sac or a vaginal pros- 
tate." ** 
Distribution: North America. 
*Pilsbry, Guide to Helices, p. XXVIII. 
**#\W. G. Binney, Man. Amer. Land Shells, pp. 79 and 83. 
