PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM, 525 
tinct. Not only do the segments of S. lactarius greatly exceed in num- 
ber those of the curious little Lysiopetalids now under discussion, but 
the secretion from the foramina repugnatoria of the former must be 
copious, for Say remarks that “when irritated it discharges a lacteous 
globule from the lateral portion of each segment, diffusing a strong and 
disagreeable odor”. And Cope remarks (Proc. Am. Ent. Soc., 1870, 
p. 67) that “ Spirostrephon lactarius exudes from a series of lateral pores 
a fluid which has in its odor a strong resemblance to creosote”. Whether 
the genus Scoterpes is well enough characterized by the absence of eyes 
may be a matter of opinion; otherwise the form agrees too closely with 
Trichopetalum to warrant us in being certain that it is not closely related. 
Both 8. (Scoterpes) copei and the three known species of Trichopetalum 
have no lateral pores, according to their describers, and are therefore 
probably a pretty closely related group, especially since they closely 
agree in the number of segments and the arrangement of the hairs or 
bristles on the back. The figure given by Packard (Am. Naturalist, 
v, 1871, p. 749) does not enable one to decide if it is male or female, on 
account of the carelessness of the artist with the first five pairs of legs, 
though it appears as if it were a female. Moreover, in the figure of the 
head from the front he contradicts his description on page 748, where 
he says: “‘ No ocular depression behind the antennz, the surface of the 
epicranium being well rounded to the antennal sockets.” The figure 
130 a, on page 749, would fairly represent the front of the head-of the 
species which I shall describe farther on, only that the antenne are 
relatively longer in Dr. Packard’s species. 
Taking a retrospective glance at the genera of American Lystopeta- 
hide, we find that a single species has furnished the basis for the genus 
Spirostrephon, defined by J. F. Brandt, in 1841, in his Recueil. His des- 
cription is only comparative with other groups of Julide of equal rank; 
the family character of the Lysiopetalids (sterna rudimentary, not con- 
joined with scuta) was used by him to define the genus Lysiopetalum. 
Jn this way Spirostrephon was characterized, mainly with respect to the 
characters presented by the maxillo-labial elements. Can it be consid- 
ered safe, in view of the facts before us, to indiscriminately assign spe- 
cies to a genus which has been quietly embraced amongst the ill-defined 
forms which have been discovered since the family has been founded ? 
To the writer the answer seems to be in the negative. No reference to 
the characters assigned to the genus or the description of the typical 
species of Spirostrephon has been made by some of the authors of Amer- 
ican species of Lysiopetalide. The present systematic céndition of the 
group is not good, and we are reluctantly forced to admit that it is very 
little better than a mere list of names. While the intention is not to be- 
little any one, there has been a very manifest lack of definiteness as 
well as accuracy and completeness of the descriptions. From the des- 
eription of S. cavernarum, ? 8. vudii, and 8. copei, we would be led to 
infer that the antennze were 8-jointed, but when we observe Dr. Pack- 
