HANSEN: EXTERNAL SENSORY ORGANS IN ARACHNIDA. 249 



»lyriform organ» has been given by GauBERT, and this name 

 has been extended so as to apply both to single, isolated 

 fissures and to groups. BertkaU is the fir.^t author v\ho 

 (in 1878) found and briefly mentioned a part of the fissures 

 and groups in Araneae. In 1885 F. Dahl [b, p 9 — 10) 

 found and described a single compound organ near the distal 

 end of the up|jer side of metatarsus of all legs in Aranese; 

 that he found only this organ proves that his investigation 

 of the legs has been very superficial, and the sentence »Ob 

 dieses Organ vielleicht auch bei der Herstellung des Gewe- 

 bes dient?» is very unfortunate. In 1892 Gaubert under- 

 took a more special study of the lyriform organs, and as to 

 their hisiological structure I refer to his paper. In Epcira 

 diadeinata he found thirteen compound organs and some single 

 fissures on each leg, and besides groups or isolated fissures 

 on the palps, the antennse and the sternum. In 1893 

 I (H. J. H. a, p. 237 — 239) added a considerable supplement 

 to Gaubert on such organs in Epcira diadeinata, pointing 

 out some more fissures on the legs and other appendages, 

 and besides on the cephalothoracic shield, labium sternale, 

 the stalk, the lower side of the abdomen, and the mammiilse. 

 Gaubert found also a portion af the fissures existing on 

 the legs and palps in both suborders of the Pedipalpi, in 

 Chelonethi and Opiliones; in 1893 and in later papers I 

 showed that in these orders single fissures exist more or 

 less regularly distributed on all parts of the body, and single 

 fissures or groups of fissures on some or most of the joints 

 of all appendages, in the family Phalangioidae fissures even 

 on the two branches of the ovipositor. 



Gaubert denied their existence in Scorpions and Soli- 

 fugae. but in Scorpions I found {a, p. 142 — 145) a number of 

 fissures, many of them arranged in groups, on second to 

 sixth jomt of the walking legs and on second and third 

 joint of the palps, but none on the antennae or the whole 

 body. In Solifugae I found [a, p. 178 — 180) two groups of 

 fissures on the lower side of first and second joint of the 

 antennae, but none on any other appendage or on the body. 

 Among the Acari single fissures have been found by WiTH 

 in the Notostigmata and by me in Oribatidae. In the 



Entoutnl. Tidskrift. Ätg. .55. Haft, j — 4 [igij). 17 



