, 
524 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 
A 
LIST OF THE NORTH AMERICAN SPECIES OF MYRIAPODS BELONG- 
ENG TO THE FAMILY OF THE LYSIOPETALID®, WITLI A DE- 
SCRIPTION OF ABLIND FORM EFROW LURAY CAVE, VIRGINIA, 
By JOHN A. RYDER. 
Without specimens of each of the species identified by the authors 
who have described them, the writer finds himself quite unable to make 
a greatly needed revision of this group. The sexual appendages have 
not been described in Spirostrephon cesioannulatus Wood, S. copet Pack- 
ard, or 7S. vudii and S. cavernarum Cope. In the cases of the two last, 
Professor Cope, who described them in 1869, at first thought that they 
were provided with two pairs of lateral pores to each segment, and in 
the belief that Spirostrephon had no lateral pores he proposed the genus 
Pseudotremia. He afterwards seemed to agree with Packard that the 
last-named genus was not valid, and appears to have considered the 
P. cavernarum a Spirostrephon, as he adopts the last name as its genus 
in his paper on the Wyandotte Cave fauna, which he published in the 
American Naturalist in July, 1872. His principal reasons for this step 
seem to have been the foregoing, and that the species was not hairy and 
was furnished with well-developed triangular eye-patches. The allied 
form found by Mr. Cooke in the Mammoth Cave has been described by 
Dr. Packard as Spirostrephon copei.”. And, Professor Cope continues, 
‘Tt is eyeless, and is, on this account alone, worthy of being distin- 
guished generically from Spirostrephon, though the absence of pores, 
asserted by Dr. Packard, would also constitute another character. Spi- 
rostrephon possesses a series of lateral pores, as I have pointed out in 
accordance with Wood’s view.” At this point Professor Cope refers to 
a paper by himself in the Proceedings of the American Entomological 
Society for 1870, where, in a foot-note, he says: “I must correct my 
character ‘no lateral pores’ for Spirostrephon (Proc. Am. Phil. Soe., 
1869, p. 179) to one series of pores’” He then proposes the genus 
Scoterpes for Packard’s Spirostrephon copei. We are accordingly led to 
believe that he has abandoned the genus Pseudotremia. But when we 
come to learn the character of the external generative organs of the 
forms described by both Cope and Packard, I would be greatly disap- 
pointed if it was not found necessary to separate S. cavernarum, ?S. 
vudii, and S. cesioannulatus Wood from Spirostrephon and refer them to 
another genus: For it is a very singular fact that, out of eight species 
of Lysiopetalide which have been described since the S. lactarius of Say, 
none are known to have more than 32 or less than 28 segments, while 
the type species has no less than 59, according to Wood. I am there- 
fore inclined to believe with Cope that the S. cesioannulatus is congen- 
erie with 8. cavernarum and S. vudii, for which the name Pseudotremia 
would perhaps become available in case they should be found to be dis- 
