462 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
Historical Review. 
It will be more convenient to review the literature that has been 
accessible to me in two parts: first, those papers which deal with the 
systematic position of Scutigerella, and second, those treating of the 
anatomical details. 
Systematic. — According to Latzel ( 84 ), the first of these forms 
known to science ( Scutigerella nivea ) was described by Scopoli in 
1763 as a Seolopendra. 
The second, called by Gervais Geophilus junior in 1836, he recognized 
as a distinct genus in 1839, and named it Scolopendrella notacantha . 
In 1884, Newport described Scolopendrella immaculata, now Scuti¬ 
gerella immaculata, which is the most common and most widely dis¬ 
tributed form of the group. 
Ryder (’ 80 ) instituted a new order for these animals, the Symphyla, 
indicating by the name the combination of myriapodean and thysanu- 
ran characters which characterizes the group. 
In 1882, Ryder separated the species of the order into two genera, 
Scutigerella and Scolopendrella, on the character of the dorsal scutes. 
Ryder (’ 80 ) also described a species of Scolopendrella — S. gratiae — 
which was withdrawn by Latzel (’ 84 ) as a synonym for Scutigerella 
nivea Scop. 
Scudder (’ 83 ) published a species, Scolope?idrella latipes, which was 
not included by Latzel (’ 84 ) in his list and is cancelled by Hansen 
(’ 03 ) as incompletely described from imperfect material. 
Latzel (’ 84 ) gave full descriptions of the three species then known 
to science, Scutigerella immaculata, S. nivea, and Scolopendrella nota¬ 
cantha. His description of the larval forms as far as known and the 
habits of the animals is very complete. 
Grassi ( 86 ) described a fourth species, Scolopendrella isabellae, 
which as an adult has but eleven pairs of legs instead of the twelve 
pairs more usually found. 
Hansen (’ 03 ) reviewed the whole order and described ten new Scuti- 
gerellas and nine new Scolopendrellas. He also re-established 
Scolopendrella microcolpa published bv Muhr (’ 81 ) and withdrawn by 
that author as a synonym of S. notacantha Ger. in the following year. 
Hansen’s new species are as follows: 
