CENTRUKOIDES. 



25 



iffusus, nov. (Tab. VI. figg. 2, 2 a, c? $ •) 



$ 



J 



patch in front of and involving the eyes, and a pair of irregular broad bands extending from the ocular 

 tubercle to the posterior border, sometimes uniting in the middle line, sometimes encroaching on the 

 lateral area of the carapace; legs, chelse, lower side of tail, and upperside of chelicerse indistinctly 

 speckled or uniformly pale ; lower side of tail with traces at least of a median band. Structurally 

 resembling female of C. elegans, but the subaculear tubercle much nearer to the base of the aculeus. 



Pectinal teeth 18. 

 <$ . Like $ in colour. Structurally differing from the male of C. elegans in the form of the tail ; this organ 



much longer and thinner, being about seven and a half times as long as the carapace, which is as long as 

 its first segment, but less than half the length of the first and second segments taken together ; fifth 

 segment as high as wide, a little more than four times as long as high ; vesicle long and oval, more 

 than twice as long as high ; subaculear tubercle close to base of aculeus. Pectinal teeth 23-24. 

 Measurements in mm. — $ . Total length 46, carapace 4-5, tail 27. tf (type). Total length 62, carapace 5, 

 tail 40 ; length of fifth segment 8, height and width 1-5 ; width of first segment 2, length 5 ; length of 

 third 7*8, width 1-8 ; length of vesicle 4, height 1-5. 



» 



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Ilab. Mexico, Ventanas in Durango (Forrer), Durango (type, A. Duges), 



This description of the subsp. suffusus is taken from a male sent by Dr. Duges and 

 a young female example from Ventanas, both being from Durango. In addition to 

 these, and a young specimen from the latter locality and a second male from Durango, 

 the British Museum has many individuals of the typical form collected by Mr. William 

 Taylor at San Diego and Duval in Texas. Say records the species from Georgia and 

 Florida, and Wood states that it ranges through the Southern Atlantic States into 

 Texas and Southern Kansas. It also occurs in California, if, as has been asserted 

 (cf. infra, p. 26), C. californicus, Gir., be the same species. 



Between the Texan and Mexican examples there are observable slight differences, 

 both in colour and structure, which warrant the separation of the latter as a distinct 

 subspecies. The two may be contrasted as follows : 



a. Anteocular triangle with sharply defined lateral edge ; subaculear 



tooth in female remote from base of aculeus, as in C. elegans ; in 



male the tail shorter and thicker, first segment much less than 



twice, third, much less than thrice as long as wide ; vesicle more 



elongate, with its aculeus less curved vittatus, Say (Texan forms) 



b. Anteocular patch with irregularly defined lateral edge, the whole 



of the upperside of the carapace more generally suffused with 

 black ; subaculear tooth close to base of aculeus in female ; male 

 with very long and slender tail, the first segment more than 

 twice, the third at least thrice as long as broad ; vesicle higher, 



# 



. ■ 



The largest female example of the typical form from San Diego gives the following 

 measurements : — Total length 68 mm., carapace 6'5, tail 42 ; and the largest male the 

 following :— Total length 55 mm., carapace 5, tail 37; width of first segment 2-5, 

 length 4-5 ; width of third 2'3, length 6 ; width of fifth 2, length 8. 



Arachn. Scorp., August 1902 



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