Scudder — Fossil Insects of North America, 219 



twice as broad as \on^ ; the angles are well rounded ; the front is 

 defeply excavated, and the two lobes thus formed have elevated bosses. 

 The second segment is a little larger than the first, and is regular in 

 form, twice as broad as long, and has rounded sides. The third and 

 largest segment of the body is twice as broad as the second, but of 

 the same form and proportions ; the rest are of a similar form, but 

 grow very gradually smaller, and, toward the extremity of the 

 abdomen, proportionally longer. The last segment is no broader 

 than the second, and nearly square, with rounded angles : a dorsal 

 mark, consisting of two impressed lines, lying parallel and close 

 together, extends the whole length of the body. 



Where the dorsal surfaces are exposed, there are no signs of 

 appendages, but, in a single case, the upper surface seems to be 

 presented to view. Here, the anterior extremity is imperfect, but 

 on either side of the first three segments which are preserved, slight 

 elevations appear to be indications of legs. The inner edges of 

 these elevations are bent at right angles, the angle being directed 

 inward and rounded off, so as to make the elevations appear almost 

 crescent- shaped ; on the outer side, the elevated portion slopes 

 gradually away. The segments composing the body are widely 

 separated from each other, and, in many cases, actually parted; 

 they must have been of a horny, or, at least, a coriaceous texture, 

 with a slighter connecting membrane. Fragments, consisting of 

 one or two segments, are scattered about on the stones. 



The drawings given by Dr. Hitchcock are inaccurate, if the speci- 

 mens before me belong, as I suppose, to his species. He has figured 

 them with lateral appendages of a peculiar character. I believe these 

 do not exist — but, that, in all cases, the sides of the segments are 

 regularly and symmetrically curved. Unless they are examined with 

 great care, one might easily believe in such a lateral prolongation of 

 the segments, but this appearance is always owing either to the 

 imperfect state of the specimens or to their incomplete exhibition 

 upon the stone. It was chiefly on account of these appendages that 

 Dr. Le Conte referred the insect to the Ephemerina. 



There is but one specimen on Professor Marsh's slab where the 

 anterior segments are well defined ; even here, they have a deceptive 

 anomalous appearance, similar to the large drawing in Dr. Hitchcock's 

 last work. 



Judging from the form of the Mormolucoides, from its being pro- 

 vided with feet on the thoracic segments alone ; and, from the fact, 

 that all the segments were evidently formed of hard shells — I am 

 convinced that the remains must be larvas of coleopterous or neurop- 

 terous insects. The nature of the segments, indeed, would be in 

 exact keeping with a myriopodal character, but the absence of any 

 indication of legs upon the posterior segments, and the small and 

 fixed number of the segments themselves, prevent our referring them 

 to that group. The slight development of legs seems to preclude the 

 possibility of their belonging to Neuroptera, and we are thus inclined 

 to consider them coleopterous larvas. They certainly remind one of 

 some Cehrionidce, but the only known larva of that group lives on the 



