r 
526 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 
ard’s figure of the last species (Am. Nat., v, p. 749) we find that there 
are but seven joints represented, which is in agreement with what we 
find in Trichopetalum, Zygonopus, Craspedosoma, and Lysiopetalum ; and 
in the case of the two first, Professor Cope’s virtual assignment of them 
to Spirostrephon makes the number of joints in their antenne doubtful. 
Trichopetalum Harger, might probably have been more closely defined 
as to its generic characters, since those given by its author would not 
define it from Zygonopus, and it differs only from S. (S.) copet in having 
eyes, from Craspedosoma in having free sterna, though the latter may 
have free sterna too. Mr. Harger, however, admits the diffiuelties which 
beset him, at page 119, in a foot-note (Am. Jour. Sci., iv, 1872). 
While examining some living specimens of Trichopetalum lunatum 
under the microscope, about a year since, I observed that the respira- 
tion of the animal appeared to be conducted in a most singular man- 
ner. The air seemed to be drawn in under the labrum and in some way 
to enter the dorsal cardiac sinus as bubbles, which could be traced for 
some distance, more than half the length of the animal, as they trav- 
eled slowly backwards, until they disappeared over the opaque mass of 
ingested food contained in the intestine. These bubbles of air always 
passed backwards. It may have been that they passed backwards in- 
si le of the intestine, but the impression I got was that they were trav- 
eling through the cardiac sinus or dorsal heart of the animal. This 
circumstance may explain why it is that there are no pores on the side 
of the body, though it is true that the lateral pores of millipeds are 
usually foramina repuguatoria, and have nothing to do with the trachea 
or respiratory apparatus. This raises the question whether our Lysi- 
opetalide are not distinguished from other forms in some more impor- 
tant way than has been hitherto supposed. 
The species which have been described are the following, though it is 
to be understood that they are only given as a list for reference; no ar- 
rangement is yet possible and none is attempted : 
1. SPIROSTREPHON LACTARIUS Say, Wood (Trans. Am. Phil. Soce., n.s., 
xiii), Art. Myriap. of N. Am., p. 192, with synonomy; Cope, Proce. 
Am Phil) Soc:2 xi; sp: 179. 
Habitat.—Eastern United States. 
2. S. CASSIOANNULATUS Wood, op. cit., p. 194. 
Habitat.—ANegheny County, Pennsylvania. 
Length 1 inch. 
3. PSEUDOTREMIA CAVERNARUM Cope, Proc. Am. Phil. Soe., xi, p. 179, 
1869; Cope, Proc. Am. Ent. Soe., ili, p. 67, 1870; Packard, Am. Nat., 
v, p. 749, 1871.—Spirostrephon cavernarum Cope, Am. Nat., vi, p. 
414, 1872.—P. cavernarum Harger, Am. Jour. Sci.,iv, pp. 118, 119. 
1872. 
_ Habitat—Caverns in Virginia and Indiana. 
Length 11 lines. 
