Its compound chaetae are heterogomph, with short or long blades, sometimes bidentate, unidentate, or a combination of both . ref name = " Authority " />
12.
It counts with one pair of fascicle; its blades are thin and unidentate, with their lengths showing dorso-ventral gradation, dorsal ones measuring a maximum of 14 �m, while ventral ones 10 �m.
13.
In the genus definition it says " Small unidentate spiders ranging from about 1.4 to 3.0mm in length . " A precise definition of the genus was provided by Gertsch & Ivie ( 1955 ).
14.
The blades of the dorsal compound chaetae possess marginal spines about 12�m long, while the blades of ventral compound chaetae are smooth, measuring about 9�m long . " Sphaerosyllis voluntariorum " shows dorsal simple chaetae from chaetiger 1, unidentate with few spines.
15.
They usually count with a short proventricle, itself provided with large muscle cell rows, large posterior acicula ( which is distally bent at 90?), blades of compound chaetae which are short and unidentate, and offspring developing ventrally, females without capillary notochaetae, only present on males . " Sphaerosyllis horrockensis ", " Sphaerosyllis belizensis ", and " Sphaerosyllis centroamericana " were transferred to " Erinaceusyllis " under these distinguishing characteristics.
