18 Dr. A. C. Stokes on some 



dorsal antenna. If present they must be exceedingly delicate 

 and minute. 



The bottom of the dorsal furrow is elastic, as the animal 

 can draw the lateral wings toward each other. 



Tapkrocampa clavigera^ sp. n. (PI. VIT. fig. 2.) 



Exceedingly soft, flexible, and versatile ; normally sub- 

 cylindrical or subfusiform, usually widest near the middle, 

 tapering posteriorly, often producing a postero-central con- 

 striction with margins almost straight; dorsum arched, 

 ventrum hollowed ; not conspicuously annulose, but the body- 

 margins irregularly crenate or undulate, these projections not 

 rarely becoming obsolete ; front rounded and bearing a hook- 

 like projection, visible in side-view much as with Taphro- 

 cawpa Saiindersue^ Gosse ; anterior region frequently re- 

 tracted j tail represented by a small semicircular lobe dorsad 

 to the soft and flexible subcylindrical foot ; toes two, short, 

 stout, conical, and possessing independent movement, being 

 therefore true toes ; a small rounded auricle frequently pro- 

 truded on each side of the head, and so accelerating the 

 animal's movements that it is difficult to observe the 

 form and structure ; dorsal cuticular surface conspicuously 

 striate longitudinally or finely fluted, the strise coarse and 

 more or less parallel with the marginal crenulations ; dorsal 

 antenna single, represented by a circumvallation near the 

 frontal border, and probably setigerous, although I have 

 not actually seen tlie seta?; frontal cilia prone, fine, short, 

 filling an obovate field which occupies from one fourth to one 

 fifth of the anterior ventral surface, and surrounded by nume- 

 rous subparallel strige or fine cuticular folds ; brain con- 

 spicuous, elongate-saccate, from one fourth to one flfth as 

 long as the entire body, and having a small, posterior, central 

 subspherical lobe, which is often coarsely granular, these 

 freely movable granules extending toward the front of the 

 ganglion in a long, narrow, sinuous band, the whole collec- 

 tion then being irregularly subclavate ; in some specimens 

 this granular formation is entirely absent or the posterior 

 lobe may alone be granular; eye red, situated on the fore 

 part of the posterior cerebral lobe, which is not rarely appa- 

 rently adherent to the mastax, the movements of which it 

 then accompanies ; intestinal canal continuous, apparently 

 ciliated, widest anteriorly, in lateral aspect suddenly narrowed, 

 and tapering posteriorly, often annulose ; oesophagus not 

 observed ; a coarsely granular body, presumably the ovary, 

 ventrad to the alimentary canal and extending for almost its 



