Abstract xi 



than two eyes are met with, but we believed that tliis would iirobably ])rove to be erroneous. 

 According to the literature of the subject nearly all animals of the suborder Cyphojjhthalmi 

 possess one pair of eyes situated on big immovable stalks, and in the genus Stylocellus a pair 

 of sessile eyes in addition in front of the stalked ones. Some years ago Dr. Purcell told one 

 of us that a small form belonging to the Opiliones ejected a liquid through " a short tube 

 resembling strongly an eye-stalk " and situated on the side of the cephalothorax. He lent 

 us a number of specimens of this form which proved itself to be allied to Siro, a genus 

 of Cyphophthalmi ; it is described by us as Purcellia illustrans n. gen., n. sp. An anatomical 

 investigation of this form, of a species of Stylocdlus and of two other genera, gave the 

 result that the terminal small areas on the processes hitherto regai'ded as eye-stalks are not 

 eyes but openings of the odoriferous glands ; such glands are well known in the two other 

 suborders of Opiliones, and their openings are seen on the surface of the cephalothorax 

 near or on its lateral margin. The sessile eyes known in Stylocellus are real eyes ; Stylocellus 

 has thus only one pair of eyes and the other Cyphophthalmi are blind ; it may be added 

 that in two blind genera a seta deviating in aspect and insertion from the other setiv on 

 the animal, and certainly being a kind of sensory organ, was found on the place corresponding 

 to that where the eye is found in Stylocellus. 



In the literature of this subject eleven species have been established as belonging to the 

 Cyphophthalmi. One of them must be referred to another suborder; of the remaining species, 

 referred to four genera, we have examined seven and are able to add seven new species. We 

 have thus examined in all fourteen species, referred by us to six genera, and only one genus, 

 and that probably of no great interest, is unknown to us ; the genus Gibocellum Stecker, being 

 a fabrication, must disappear. By dissecting representatives of four genera we have been able 

 to give a complete account of the dermoskeleton, and to fill up several of the gaps in the 

 knowdedge of the inner anatomy, of which almost nothing was known. The Cyphophthalmi 

 are a well-founded suborder, containing a single family, the Sironoidas ; the characters es- 

 tablished by earlier writers for the family or the suborder were but few and most of them 

 even incorrect, a fact easily explained by the smallness of the animals and the very scanty 

 material which those writers had at their disposal. We point out a long series of characters 

 for this suborder, and give besides a revision of the characters for the Palpatores and Lania- 

 tores, basing that revision on a renewed study of representatives of all families of these 

 suborders and adding several new characters for the families of Palpatores, for the two 

 last-named suborders, and for the order Opiliones. 



