1870.] 303 [Burgess 



downward ; basal process not quite so long as in the N. Horatius, and 

 the whole apical half enlarged. Lobe projected further backward 

 than in iV. Horatius, forming a longer and more slender triangle. 



Right clasp : Main body quite as in JSF. Horatius, but a little broader. 

 Blade also similar, but broader throughout and at the tip nearly one 

 half as broad again as in the middle ; basal process consisting of a 

 small, elongate, subtriangular tooth, nearly uniform in width, bluntly 

 pointed, fully twice as long as broad at the base and as long as the 

 narrowest breadth of the blade, directed straight backward. Lobe 

 as in N. Horatius, but a little larger and longer and scarcely so much 

 incurved. 



New England. 



GROUP VII. 



Upper organ: crest greatly elevated, expanded laterally into very 

 large, curving, prickly, asymmetrical flaps; hooks and tooth as in 

 group V. Clasps : much as in group VI. 

 Nisoniades tristis (Boisduval.) Fig. 15. 



Upper organ : Main body long and rather slender, not high, some- 

 what arched ; posterior extremity of the upper surface strongly ele- 

 vated and then expanded laterally into very unequal, outward and 

 downward curving alations, that of the left side forming an exces- 

 sively enlarged, broad, rounded lobe, the lower anterior portion 

 bent downward more than the other and produced anteriorly to a 

 considerable extent ; the whole upper surface and edges and a por- 

 tion of the under surface are covered with minute raised points, which 

 become developed on the anterior edge into distinct spinules ; that of 

 the left side form a very long and slender, slightly sinuate, unarmed 

 plate, somewhat constricted toward the base, the tip well rounded, 

 not quite as long as that of the opposite side. Hooks moderately 

 stout, short, arching, pointed, scarcely divaricate, rather distant at 

 base, the right nearly abortive ; tooth appressed, subcordate, with 

 compressed neck, projecting downward and very slightly backward, 

 the edges unarmed, emarginate. Arms slender, tapering slightly, di- 

 rected downward, with a slight anterior curve, bent backward abrupt- 

 ly at less than a right angle and then directed backward, upward 

 and inward, bearing between their tips the inferior armature, a rather 

 small, asymmetrical, reniform field of raised points. 



Left clasp : Main body very broad, uppermost portion of the base quite 

 full, lower edge very slightly curved ; longitudinally nearly straight, lat- 

 erally but slightly gibbous. Blade long, directed almost horizontally 



