84 PROCEEDINGS OF THE ACADEMY OF [1881. 



from twelve to twent3'-eiglit, and finds specimens of different ages 

 ■with nine, ten, eleven and twelve pairs of legs. This variability 

 in the number of pairs of legs I have noticed m both the American 

 forms studied by m^'self. Newport also at first thought the 

 creature was nearly related to Geophilus, but afterwards placed it 

 between Lithobius and Scolopendra^ but he at last considered it 

 the type of a family, a conclusion which Gervais^ did not accept. 

 Wood^ says he never saAV any specimens of the famih^, and gives 

 the characters assigned by Newport. 



The first species described was by Gervais in 1839, from speci- 

 mens found in the environs of Paris. This species was made the 

 type of the genus. In his description he disagrees with Menge in 

 the distribution of the legs. This ma}' however be on account of 

 the difference of the species. 



Order SYMPHYLA. 

 Amer. Nat. XIV, p. 375-6. 

 Head, antennre and mouth parts thysanuriform. Trachea as 

 tubular arches without spiral filament. Spiracles within the bases 

 of the legs. An orifice on the ventral side of the bod}' opening on 

 the third (young) or fourth (adult) body -segment ; present in some 

 individuals as a pore, in others as a longitudinal cleft, closed by 

 means of an oblong chitinous piece on either side, the two together 

 occupying a subquadrate space. Two Malpighian tubules (four 

 Menge). Legs five-jointed, terminated by a pair of claws. Ven- 

 tral appendages at the bases of each pair of legs except the first. 

 Caudal stylets containing spinning glands which open at their 

 tips. Ovary lying dorsad of the rectum (Menge). 



Family SCOLOPENDRELLIDJE. 



Newp. Transac Linn. Society, XIX, p. 374. 

 SCOLOPENDRELLA Gerv. 

 Comptes Eendns, 1839. 



S. notacantha Gerv. Apteres, IV, 301, PI. 39, fig.- 7 ; Ann. Sei. Nat., Zool. II, 1844, 



p. 70, PI. 5, figs. 15-17; Ryder, Am. Nat., p. 375, 1880. Hab. France and ? Pa. 



and Md. 

 S. immaculata Newport. Trans. Linn. Soe. XIX, pp. 373-374, PI. XL, figs'. 4, 4a, 



b, c; Menge, Neuste Schr. d. naturf. Gesell. Danzig, IV, 1861, Pis. 2, Hab. 



England and Germany. 



^ Apteres. Suite a Buflfon, Walckenaer et Gervais, t. IV, p. 301-308. 

 Paris, 1847. 



- Monogr. North American Myriap., Trans. Am. Philos. Soc, XIII. New 

 Series, 1869. 



