252 MR. p. PICKARD CAMBRIDGE ON THE [Apr. 15, 



h. Eyes of anterior row not equidistant, centrals 

 nearer together than to the laterals i. 

 \_Note. — The following three species are, so far 

 as I am able to judge from the material at 

 hand, all of one fundamental form, namely, 

 tredecim-ffuttatus Pabr., but they fall 

 into certain groups more or less limited 

 by locality. Subjoined are the characters 

 of extreme examples.] 

 a^. Legs of first pair longer in proportion ; 

 tibia i. at least one-fourth longer than 

 the carapace. 



1. Abdomen either entirely black or brown, or 



with a central red band more or less broken 

 up into distinct spots and three or more oval- 

 elongate lateral spots. Ventral spot either 

 absent or represented by a transverse band 

 immediately below the genital rima, and often 

 one above the spinners; probably also con- 

 fluent, forming a larger spot tredecim-guttatus Rossi. 



2. Abdomen black, with an oblong-oval, central, 



posterior apical red spot, with three very small 

 white spots on each side. Ventral spot usually 

 represented by a transverse bar below the 

 genital rima menavodi Vinson. 



3. Abdomen black, with a single central longi- 



tudinal red band, anteriorly either constricted 

 or broken off to form a separate spot. Ventral 

 spot either absent or with one or two trans- 

 verse spots, or with a large dumbbell-shaped 



blotch hasseltii Thorell. 



6 2. Legs of first pair shorter in proportion ; 



tibia i. not longer than the carapace. 



Spider usually smaller katipo Powell. 



II. List of Species and Sub-species recognized in this Paper. 

 (For references and dates of synonyms, see Alphabetical List.) 



1, Latrodectus hystrix E. Simon, 1889. (Plate XXYI. fig. 2.) 



(Species.) 



This form is quite distinct from any others that have been 

 taken in any part of the world, being clothed with short, stiff, 

 stout black spines, and cannot be mistaken for anything else. 

 Posterior row of eyes straight, approximately equidistant ; centrals 

 one diameter from each other, slightly further from the laterals. 

 Posterior centrals much larger than the anterior centrals. Central 

 anteriors less than one diameter apart, one diameter from the 

 laterals, and distinctly smaller. Laterals half a diameter apart. 



The example figured was kindly lent by M. E. Simon, and 

 another example was found by Col. Yerbury at Aden. 



Hab. Aden (Simon and Yerhury). 



2. Latrodectus geometricus C. L. Koch, 1841, (Plate XXVII. 

 fig. 7.) (Species.) 



Synonym. L. zickzach (Karsch), sub Theridium. 

 This form is more distinct from the others than any except 

 1 See note on p. 251. 



