83.2 Mr. J. Blackwall on the Structure, Functions, (Economy, 



Fig. 7' Balanus porcatus, abdominal view, just liberated from the ovum. 



— 8. Clitia Stromia, do. do. do. 



— 9. The same after the first moult ; abdominal aspect. 



— 10. The same after the first moult; dorsal aspect. 



— 11. Chthamalus depressus, first form, abdominal view; 11 a, caudal 



extremity. 



— 12. The same after first moult ; dorsal as])ect. 



— 13. The same after first moult ; abdominal view. 



— 14. The same, lateral view. 



— 15. Balanus balanoides : the pupa, or stage of the larva immediately 



previous to its becoming a fixed animal, in a state of activity. 



— 16. The same at rest. 



— 1/. The same, viewed in front. 



— 18. The same, anterior member with sucker and hooks. 



— 19. The same, posterior natatory leg and caudal appendage. 



— 20. The same, soon after its becoming fixed. 



— 21. The same, do. seen from above. 



— 22. The same, a little older. 



— 23. a, Spermatozoa of Balanus balanoides. 



b, do. do. Balanus perf or atus. 



c, do. do. Clitia Stromia. 



XXVII. — A Catalogue of British Spiders, including remarks on 

 their Structure, Functions, (Economy and Systematic Arrange- 

 ment. By John Blackwall, F.L.S. 



[Continued from p. 102.] 



77. Agelena celans. 



Agelena celans, Blackw. Linn. Trans, vol. xviii. p. 624. 

 Argus celans, Walck. Hist. Nat. des Insect. Apt. t. iv. p. 504. 



This scarce species may occasionally be met with running upon 

 the ground or concealed under stones in woods about Llanrwst. 

 The palpal organs of the male are developed in August. Though 

 intimately allied to the ^^e/ew«, yet M. Walckenaer has included 

 this spider in the genus Argus. 



Genus Tegenaria, Walck. 

 78. Tegenaria domestica. 



Teyenaria domestica, Walck. Hist. Nat. des Insect. Apt. t. ii. p. 2. 



pi. 16. fig. 2; Koch, Die Arachn. B. viii. p. 25. tab. 260. fig. 607, 



608 ; Blackw. Linn, Trans, vol. xix. p. 117. 



petrensis, Koch, Die Arachn. B. viii. p. 27. tab. 260. fig. 609. 

 Aranea domestica, Latr. Gen. Crust, et Insect, torn. i. p. 96. 

 Agelena domestica, Sund. Vet. Acad. Handl. 1831, p. 125. 

 Philoica domestica, Koch,Uebers. des Arachn. Syst. erstes Heft, p. 13. 



I have received specimens of Tegenaria domestica from Cam- 

 bridgeshire, Oxfordshire and Middlesex; but I have not ob- 



