i6» 



Gar dins. 



20. 



Hirudo, 





b; 



175 



Lumbricus, 



19. 



Sipuncultis, 



6 W O K M S. 



Body equal filiform round and fmooth: 

 Body truncate at each extremity : head and 

 tail dilated when in motion. 



Perforated with a lateral Pore, 



Body round annulate, fumifhed with minute 



concealed prickles. 

 Body round: mouth cylindrical and narrower 

 than the head. 

 18. Planar la. Body deprefled, with a ventral pore: 



II. MOLLUSCA. Simple animals furnifhed with limbs. 



A. Mouth placed above, 



3^. - Aclinia. Body fixed, with a fingle terminal dilatable 



aperture furrounded by tentacula or cirri. 



34. Clava, Body fixed, with a (ingle dilatable vertical 



aperture furrounded with clavate tenracula. 



37. Pedicellaria, Body fixed and furniihed with a rigid pe- 



duncle. 

 36. Mammaria* Body loofe fmooth, with a fingle aperture 



without cirri. 



31. Ajcidia^ Body fixed; with 2 apertures, one of which 



is terminai,theother placed alittle beneath . 



32. Salpa, Body loofe ; with 2 apertures, one at each 



end. 



33. Dagyfui* • Body loofe angular, open at each end. 



B. Mouth placed before* 



39. Pterotrachea, Body pervious gelatinous, with a moveable 



fin at the head or tail. 



40. Derris. Body round tapering articulate: feelers 2, 



C. Mouth placed before : bod)' with a lateral perforation, 



21. Limax, Feelers 4: vent common with the lateral 



pore. 



22. Laplyfta, Feelers 4: vent placed above the lower ex* 



tremity. 

 24. Doris, Feelers 2 : vent above the lower extremities. 



38. Tethys. Body with 2 fmall pores on the left lide. 



D. Mouth before : body furrounded with feelers en the fore-part, 



4 1 ; Holothtirie.t 



