328 Mr. F. 0. P. Cambridge on 



Though the species are very variable individually, they may 

 be recognized by the following characters : — 



A. Abdomen with four spines only, median 



and posterior. 



1. Spines short, triangular, and equal in 



lenjrth. Colour variable. Carapace 

 and legs varying from bright orange- 

 red, tTie latter annulate, to black 

 throughout ; in this case there are deep 

 cyanine reflections. Abdomen black 

 or yellow, with black margins and 

 blotches. Sternum aud ventral area 

 of abdomen black, the latter often with 

 more or less yellow round the spinners 

 and with yellow spots near posterior 

 margin tetracantha, Linn. 



2. Spines longer and more conical, unequal 



in length. Medians longer and stouter 

 than the posterior spines. Colour vari- 

 able. Carapace and legs bright orange- 

 red, the latter annulate or entirely 

 black. Abdomen entirely yellow or 

 entirely black ; spines orange-red or 

 black * Canestrinii, 0. P. Camb. 



B. Abdomen with six spines. 



1. Abdomen (not including spines) about 



one fourth broader than long. Spines 

 miequal, anterior smaller than median, 

 often obsolescent. Lateral spines longer 

 than the posterior. Colour very vari- 

 able. Carapace and legs bright orange- 

 red, latter annulate or entirely black. 

 Abdomen entirely black or entirelj' 

 yellow, or yellow more or less varie- 

 gated with black or vice versa. Yen- 

 tral area of abdomen usually black, 

 spotted throughout with yellow. Spines 

 orange-red or black ? cancri/onnis, Linn. 



2. Abdomen (not including spines) about 



one half broader than long. Spines 

 equal (anterior and median), posteriors 

 larger. Anterior and median spines 

 very small and sharp. Colour similarly 

 variable. Anterior angles at the base 

 of the spiues and base of medians often 

 ■with a laro-e rounded blotch, black on 

 yellow. Ventral area black, often lined 

 with yellow, but not spotted Eochii, Butler. 



Gasteracantha tetracantha (Linn.). 



Aranea tefracantlm, Linn. Syst. Nat. ii. p. 1037. no. 45. — St. Thomas. 

 Gasteracantha pallida, C. K. (Marx), Die Arach. xi. p. 60, fig. 881.— 



California. 

 G. quadridem, C. K., t. c. p. -59, fig. 880.— St. Thomas. 



