364 NATURAL SCIENCE. Nov.. 



The memoir of Dr. Hansen (4), already mentioned, adds con- 

 siderably to our knowledge of sense-organs in arachnids, supplementing 

 in many respects M. Gaubert's researches, already reviewed in Natural 

 Science (vol. i., p. 525). Lyriform organs were not observed by M. 

 Gaubert in scorpions or in Solifugida. Dr. Hansen has found them 

 on most of the joints of all the walking legs, and on two joints of the 

 palps, in both Scorpio and Buthns ; and also on the middle finger of 

 the cheliceras of various genera of solifugids. He has noted them, 

 too, in various regions of arachnids of other orders where they had 

 not been seen by M. Gaubert. In a series of ridges and furrows 

 upon the inner face of each chelicera in solfugids, Dr. Hansen believes 

 he has discovered a peculiar stridulating organ. He describes and 

 figures many interesting varieties of tactile hairs and other sense- 

 organs. A specially interesting discovery is that of two air-stigmata, 

 one at the proximal and one at the distal end of each of the eight 

 tibiae of the legs oi Phalangiiim and some harvestmen of other genera. 

 The existence of such stigmata on limbs is claimed by Dr. Hansen as 

 unique among arthropods, and seems a special adaptation to ihe 

 excessive length of leg characteristic of the Phalangiidae. In the 

 other families of the order, whose legs are relatively shorter, these 

 stigmata appear to be absent. 



In his publications on arachnid morphology, Mr. Bernard mentions 

 an extensive research upon the Solifugida which he has in progress. 

 A study of the animals of this order, with their imperfectly fused 

 anterior segments and other archaic characters, cannot fail to throw 

 additional light upon the points now under dispute. Mr. Bernard 

 has already issued several preliminary notes, the most interesting of 

 which (9) announces the discovery of lateral eyes in these animals. 

 Hitherto the two central eyes only had been observed. Two lateral 

 eyes have now been found by Mr. Bernard on either side of the 

 cephalothorax ; owing to the great development of the chelicerse, 

 they seem to have travelled from the dorsal to the lateral surface. 

 They appear to be degenerating, though in some cases a ganglion 

 and retinal cells can be observed. 



REFERENCES. 



Bernard, H. M.—" Additional Notes on the Origin of Tracheae from 

 Setiparous Glands." Ann. Mag. Nat. Hist. (6), vol. xi., 1893, pp. 24-28. 



" The Stigmata of the Arachnida as a Clue to their 



Ancestry." Nature, vol. xlix., 1893, p. 68. 



" Notes on the Chernetidse, with special reference to the 



Vestigial Stigmata, and to a New Form of Trachea." Jouni. Linn. Soc. 

 [Zool.), vol. xxiv., 1893, pp. 410-430, pis. 31, 32. 



4. Hansen, H. J. — "Organs and Characters indifferent Orders of Arachnids.' 



Entomol. Meddelelser, 1893, pp. 137-252, pis. ii.-v. 



5. Bernard, H. M.—" Vestigial Stigmata in the Arachnida." A.M.N.H. (6), 



vol. xiv., 1894, PP- I49~i53' 



