Spiders and Their Near Relatives 



BB. Palpus all of one colour. A small species, measuring less 

 than one twelfth inch in length, found at Ithaca, N. Y. 



Gary pus gr anu lat us 



Genus OLP1UM (Ol'pi-um) 



The cephalothorax is a little longer than wide and quite sud- 

 denly narrowed in front of the eyes; it is marked by neither trans- 

 verse nor longitudinal striae. The anterior eyes are separated 

 from the anterior margin of the carapace by a space about equal 

 to their diameter. The scutae of the abdominal segments are not 

 divided by a median longitudinal suture. The following is our 

 only known representative of this genus. 



Olpium obscurum (O. ob-scu'rum).— - This is a small blackish 

 species measuring only one twelfth inch in length; it occurs in 

 Florida. 



Family IDEOBSIID^E (Id-e-o-bi-si'i-dae) 



The members of this family resemble the Cheliferidae in 

 having the spinneret of the chelicera long, slender, and trans- 

 parent, but differ in having the serrula attached only at the base 

 to the finger of the chelicera. The carapace is not divided by a 

 transverse suture and the abdominal scutae are entire. The femur 

 and tibia of the first two pairs of legs are short and stout. 



Representatives of two genera have been found in the United 

 States; these can be separated by the number of eyes. 



A. With two eyes. p. 51. Ideoronchus 



AA. With four eyes. p. 50. Ideobsium 



Genus IDEOB1SIUM (Id-e-o-bis'i-um) 



The cephalothorax is smooth, without transverse sutures, 

 nearly as broad in front as behind. There are four distinct eyes. 

 The chelicerae are large, with a distinct spinneret. The abdomen 

 is moderately elongate, with the scutae entire. The palpi are of 

 moderate size, and with the fingers curved. The body bears 

 simple hairs. 



Only two species have been found in the United States. 



Ideobisium rufuJum{\. ru'fu-lum). — In this species the cepha- 



SO 



