CLASS iriCATIOlS" OF THE TUNIC ATA. 567 



i Small papillae on the edges of the stigmata. [Eur.) 

 M. impura. Heller. (Med., N.W. 

 -N'o such papillffi 4 



A f Dorsal tubercle elongated, not horseshoe-shaped 5 



\ Dorsal tubercle horseshoe- shaped 6 



{Dorsal tubercle nearly linear, subareuate. 

 M. eugyrokles, Traust. (S. Atl.) 

 Dorsal tubercle irregularly convoluted, serpentiform. 

 M. Holtiana, Herdm . (N.W. Eur.) 



^ f Apertm-e between horns of dorsal tubercle turned to the left 7 



I Aperture turned posteriorly , 8 



r 4 to 6 inter, longit. bars on a fold ; anus with plain free edge. 

 7 \ M. Koreni, Traust. (W. Ind.) 

 [ 2 to 4 inter, longit. bars on a fold ,.. 9 



q r Anus with a fringed edge M. simplex, A. & H. (N.W. Eur.) 



\ Margin of anus smooth M. macrosiphonica, Kupf. (N.W. 



[Eur.) 



Q fEdge of dorsal lamina entire 10 



\ Edge of dorsal lamina toothed 11 



-.r. f Anus with a plain edge M. tenax, Traust. (W. Ind.) 



\ Anus with a fringed edge 12 



[ 3 int. long, bars on a fold M. ampulloides. T.Ben. (N.W. 



12 j ' [Eur., Med.) 



I 4 int. long, bars on a fold M. socialis, Alder. (N.W. Eur.) 



.. ^ r Anus witli plain edge M. Lutlceniana, Traust. (N.W. E.) 



[ Aims with a fringed edge M. tuhifera, QErsted. (N.W. Eur.) 



1 Dorsal tubercle simple, circular, and funnel-shaped, no horns. 

 M. pyriformis, Herdm. (S. Atl.) 

 Dorsal tubercle curved, with horns 13 



,„ f Dorsal tubercle horseshoe-shaped 14- 



[ Dorsal tubercle Sshaped 15 



1 > J Margin of dorsal lamina fringed or toothed 16 



[ Margin of dorsal lamina plain 17 



f Only the posterior half of body sandy. 

 1() \ M. gigantca, Ounn. (Mag.) 



[ The whole of body sandy M. occulta, Kupff. (N.W. E., Med.) 



C Siphons retracted between folds of test ; no sand between the aper- 



17"^ tures M. ocidata,Yovb. (N.W.Eur.) 



[ No such folds of test present , , 18 



r Papillae on the margins of the stigmata. 

 18 \ M. occidenialis, Traust. (W. Ind.) 

 [ No such papillte present 19 



^q [Horns of dorsal tubercle merely turned in 20 



[Horns of dorsal tubercle coiled spirally ; aperture turned to right side 21 



nr^ /Test not sandy 22 



'^^ \ Test sandy 23 



[Outside of siphons echinated, or having pointed projections 24 



[ Siphons not echiuuted 25 



LIJfN. JOUltN. — ZOOLOGY, TOL. SXIII. 41 



