1870.] 297 [Burgess. 



and a little downward, the lower portion of apex a little produced, 

 rather laterally than apically, but rounded. 



Right clasp : Main body not broad, nearly equal, the upper portion 

 of the base largely docked diagonally. Blade long and broad, di- 

 rected somewhat upward, curved, especially near apex, a little in- 

 ward, the outer surface twisted a very little upward; it is broadest in 

 the middle and tapers beyond very gradually to a well rounded tip ; 

 basal process wanting. Lobe closely contiguous, and at base par- 

 allel to the blade, long and slender, directed a little upward, curved 

 inward; the apical half tapers suddenly to a long and very slender, 

 nearly equal, curving dactyl, directed a little downward and nearly 

 straight inward, bluntly pointed and armed at the apex with some 

 very minute spinules. 



New England. 

 Nisoniades Juvenalis Westwood. Fig. 10. 



Upper organ : Main body short and moderately high. Posterior 

 part of upper surface not greatly elevated, bearing at the extremity 

 an appressed, slightly sinuous plate, facing backward, comparatively 

 narrow at base, immediately expanding greatly, so as to appear al- 

 most sessile; the outer angles, especially that upon the right side, are 

 greatly produced and sharply pointed ; the upper border is broadly 

 arched and armed as in N. Ennius, and the median furrow is as in 

 that species. Hooks short, very broad at base, bluntly pointed, tri- 

 angular, depressed, inequally curved, divergent, distant at the base 

 by the width of the tooth, which is so hidden in the only specimen 

 we have been able to examine that it cannot be described without 

 injury. Arms much as in Ennius, but slenderer, bearing at their 

 united tips a broad belt of raised points — the inferior armature. 



Left clasp : Similar to that of N. Ennius, but differing from it in 

 the following particulars : the upper margin of the main body has a 

 slight sharp tubercle just previous to the lobe, indicated in N. Ennius 

 only by a scarcely noticeable elevation. Basal half of the blade 

 fully as broad as that of N. Ennius, while beyond the median denti- 

 cle the upper edge is considerably narrowed by a broad rounded ex- 

 cision, making this portion slenderer than in N. Ennius, and scarcely 

 more than one third as broad as the basal portion ; the apex is much 

 more produced and very finely pointed, and the denticulations more 

 distinct; the basal process differs only in having the hinder portion 

 produced to a greater length and more slender, being nearly one 

 third the length of the inner margin of the blade ; while in N. En- 



