576 SUMMARY OF CURRENT RESEARCHES RELATING TO 



cocoon rather than the pith-ball, but in tho absenco of the former will 

 content herself either with a pith-ball or a web-covered shot. The 

 carrying of the latter indicates a poorly developed muscular sense. 



Brain of Phalangida.* — M. G. Saint- Remy has examined the brains 

 of Thalangium ojjilio, and P. parietinum. He finds that tho brain may be 

 divided into two ganglionic regions ; the optic ganglion which gives 

 rise to a pair of optic nerves, and a rostro-mandibular ganglion from 

 whicli arise an unpaired nerve which passes to the rostrum, and a pair 

 of mandibular nerves which go to the chelicerae. 



Though the brain of tho Phalangida is much simpler than that of 

 Insects or Crustacea it has some points in common with them which are 

 of some importance. At the origin of each optic nerve there is a lobe, 

 of comparatively complicated structure, which is altogether comparable 

 to what is known as the optic ganglion in Insects ; the same lobe, in a 

 simpler condition, has been observed in the Scorpion and in Spiders. In 

 the optic ganglion of the Arachnida there are, further, ganglionic nuclei 

 which seem to be found in sensorial ganglia only, and have been 

 observed in Insects, Crustacea, and Myriopoda. 



S. Prototracheata. 



Monograph of the Genus Peripatus.j — Mr. A. Sedgwick has prepared 

 n monograph of tho genus Peripatus, which is based on the examination 

 of a considerable nmuber of specimens. He has been able to establish 

 a definite series of characters which distinguish quite sharply all the 

 species found in one area of distribution from those found in others. 

 The number of walking-legs varies considerably within the same species, 

 and a large number of individuals are required to determine the limits 

 of the variation. The other specific characters are very inconspicuous, 

 and relate simply to the texture and tint of the skin. 



A general account is given of the genus, within which, as is pointed 

 out, there is no gradation ; the number of species is small, and the cha- 

 racteristics of the genus are equally sharply marked in all. The long 

 continuance of this ancient form may be explained by its peculiar habits 

 of life — habitual avoiding of the light of day, and seeking the obscurity 

 and protection afforded by spaces beneath stones and under the bark of 

 trees. It is an animal of striking beauty : " the exquisite sensitiveness 

 and constantly changing form of the antennse, the well-rounded plump 

 body, the eyes set like small diamonds on the side of tho head, the 

 delicate feet, and, above all, the rich colouring and velvety texture of 

 the skin, all combine to give these animals an aspect of quite exceptional 

 beauty." 



In South Africa there are four species — P. capensis, P. halfouri, and 

 P. hrevis from Table Mountain, and P. moseleyi from near Williamstown. 

 The Australasian species are P. novae ZealancUae from New Zealand, and 

 P. leuclarti from Queensland, Australia. From the Neotropical Region 

 P. edicardsii from Caracas, P. im thurmi of Sclater (or P. demeraranus, 

 as Mr. Sedgwick proposes to call it) from Demerara, P. trinidadensis 

 (P. edicardsii Kennel) and P. torquatus, described by v. Kennel from 

 Trinidad, and P. juliformis from St. Vincent ; the Chilian species may be 

 called P. chilensis ; Schmarda has given a short description of P. quitensis 



* Comptes Rcndus, cvi. (1888) pp. 1429-31. 



t Quart. Journ. Micr. ScL, xxviii. (1888) pp. 431-93 (7 pis.). 



