SUBFAMILY ERIOCOCCINAE 125 



the ring is vertical, is considered as the cephalic end and the 

 opposite end as the caudal. The anal ring bears cerores, which 

 are arranged in two rows in Pseudococcus, the orbacerores, and 

 judging from their staining reaction are different in structure. 

 The outer and shorter row is the lateral orbacerores, the inner and 

 mesal row is the mesal orbacerores. This latter is frequently 

 continuous between the cephalic anal ring setae. Some of the 

 cerores of the mesal row in this genus are elongated and produce 

 extensions of or irregularities in the membrane surrounding the 

 anus. These cerores may be known as the dentacerores. They 

 were called denticulate pores by Smith, who was the first to call 

 attention to them. The number of dentacerores on each side of 

 the anal ring is not large, so far as observed two to four. It is 

 difficult to make good flat preparations showing the characteristic 

 number and arrangement of the orbacerores, dentacerores, and 

 anal ring setae, but my observations lead me to believe that some 

 of the best characters for the differentiation of species are to be 

 found in these structures. The importance of these characters 

 was first emphasized by P. E. Smith. Flat preparations for the 

 study of these structures can be secured only by dissecting out 

 the anal ring and mounting it separately. The anal lobes should 

 be removed and the dissecting should be done on a slide after the 

 specimens have been stained and cleared. 



There are in certain genera four prominent setae located 

 caudad or ventrad or cephalad of the caudal end of the anal ring, 

 depending upon whether the anal ring is dorsal, caudal or vertical, 

 or partially ventral. These setae are known as the cisanal and 

 obanal setae. They mark the four corners of a quadrangular area. 

 The two setae nearest to the anal ring are the longest and are 

 known as the cisanal setae. These are the cephalic postanal setae 

 of Smith. The two setae farthest from the anal ring are generally 

 smaller than the cisanal setae and are frequently located farther 

 apart. They are obanal setae, the caudal postanal setae of Smith. 



The species of this subfamily are frequently based upon the 

 comparative length of the antennal segments. Kellogg and Bell 

 and later P. E. Smith made careful studies and measurements of 

 antennae of specimens of unquestioned identity and showed that 

 characters of this sort were worthless for the separation of species. 

 Their studies went to show that there was enough variation in the 

 length of the segments of the two antennae of the same individual 



