308 
Florence Peebles. 
C. Conclusion. 
Within the last ten years several new genera have been discovered 
among the Acoela and now at least twelve have been identified and 
described two of these, CMldia and Änapems, were found by von Graff 
(1912) on the eastern coast of the United States, Rimicola was discovered 
by Böhmig (1908) on one of the Belgian expeditions, and MonocJioerus 
by Löhner and Micoletzky (1911) in the Adriatic. The following Classi- 
fication by VON Graff (1912) is given here for the sake of comparison 
with one made by Luther (1912) later in the same year. 
The Classification of the Acoela, by von Graff (1912). 
1. Acoela with a single genital opening. 
Family 1. Proporidae. 
A. Proporidae without bursa seminalis. 
aa) Definite chitinous mouth-pieces wanting. 
a) Penis simple. 
1. Pharynx a long tube, body elongated. 
Genus 1. Proporus. 
2. Pharynx wanting, or short, body shield-shaped. 
Genus 2. Haplodiseus. 
b) Penis paired. 
Genus 3. CMldia. 
bb) Several chitinous mouth-pieces present. 
Genus 4. Änapems. 
B. Proporidae with bursa seminalis, and a mouth-piece. 
Genus 5. Otocelis. 
L Acoela with two genital openings, and a bursa se- 
minalis. 
Family 2. Convolutidae. 
A. Chitinous mouth-piece wanting 
Genus 6. Aphanostoma. 
B. Chitinous mouth-piece present. 
a) With one mouth-piece. 
1. Mouth-piece opening into antrum femininum. 
Genus 7. Convoluta. 
2. Mouth-piece opening into the parenchyma. 
Genus 8. MonocJioerus. 
b) With two or more mouth-pieces. 
1. Two mouth-pieces, no tail filament. 
