76 Mr. J. Blackwall on new species of 



homogeneous membranes are formed by the excavation of the 

 cytoblasts, I beheve that he has not observed all the stages and 

 transitions of the cytoblasts into starch ; for he does not notice 

 the formation of the starch from the excavated cytoblast. The 

 formation of a homogeneous membrane (membrane-substance) 

 from the external layers of the cytoblast appears to be a very pe- 

 culiar process, which will hereafter explain how it is that this 

 membrane is not formed round a perfect cytoblast, and the trans- 

 ition of the latter into another state of aggregation (starch) . 



Still we cannot explain the whole process of the formation of 

 starch throughout the organic kingdom from these investigations, 

 which may be readily made in the manner stated. The above 

 isolated instance is insufficient; I therefore refrain from any further 

 comparison of the separate stages of the starch-formation. How- 

 ever, this example, especially as it may be so readily observed, will 

 constitute a sure starting-point from which we may trace the 

 formation of starch generally. 



XI. — Notice of Spiders captured hy Professor Potter in Canada, 

 with descriptions of such Species as appear to he new to science. 

 By John Blackwall, F.L.S. 



[Continued from p. 44.] • 



Genus Tegenaria, Walck. 

 19. Tegenaria civilis. 



Tegenaria civilis, Walck. Hist. Nat. des Insect. Apt. t. 2. p. 7; 

 Koch, Die Arachn. (Fortsetzung des Hahn'schen Werkes), B. 8. 

 p. 37. t. 264. fig. 618, 619. 



Agelena civilis, Sundevall, Vet. Acad. Handl. 1831. p. 127. 

 . Aranem subflavus, Lister, De Aran. p. 59. tit. xvii. fig. 17. 



Family TnERiDiiDiE. 



Genus Theridion, Walck, 



20. Theridion quadripunctatum. 



Theridion quadripunctatum, Walck. Hist. Nat. des Insect. Apt. 

 t. 2. p. 290 ; Sundevall, Vet. Acad. Handl. 1831. p. 118 ; Hahn, 

 Die Arachn. B. 1. p. 78. tab. 20. fig. 58. 



Eucharia bipunctata, Koch, Uebersicht des Arachnidensystems, 

 Erstes Heft, p. 7. tab. 1. fig. 13. 



Araneus pullus, Lister, De Aran. p. 49. tit. xi. fig. 11. 



