NEW MALLOPHAGA. 165 



moving any likelihood of confusing it with titan), and by 

 designating ragazzi and my specimens as varieties pre- 

 senting the following diagnostic characters: 



Var. ragazzia Picaglia, from Pelecans trachyrhynchus 

 (Callao) ; small, length of male 3.42 mm., of female 

 3.15 mm.; mesothoracic suture indistinct; metathorax a 

 little wider than the head; general color paler than titan. 



Var. impar Kellogg, from Pelecanus erythrorhynchus 

 (Lawrence, Kansas) ; with the minor differential char- 

 acters of ragazzi, but almost as large as titan; length 

 of male 4.7 mm., of female 3.8 mm. 



Var. linearis Kellogg (Plate xv, fig. 2), from Pelecanus 

 californicus; about same size as titan; length of male 5.2 

 mm., of female 4.2 mm.; transverse abdominal blotches 

 not bifurcated at extremities, and the longitudinal un- 

 colored lines beyond spiracles very distinct in female, 

 forming an interrupted, uncolored, longitudinal line for 

 full length of abdomen, setting off lateral abdominal 

 bands which are darker than the other abdominal mark- 

 ings. 



Menopon tridens Nitzsch. (Plate xv, figs. 3 and 4.) 



? Germar's Mag. Entomol., 1818, vol. iii. 



Lcbinobothrium tridens Nitzsch. Zeitzschr. f. ges. Naturwiss. (ed. 



Giebel), 1866, vol. xxviii, p. 396. 

 Menopon scopulacome Denny. Monograph. Auoplur. Brit., 1842, p. 



221, pi. 18, fig. 9. 

 Menopon tridens Nitzsch. Burmeister, Handbuch. d. Ent., 1832, vol. 



ii, p. 440; Giebel, Insecta Epizoa, 1874, p. 296, pi. xvii, fig. 9; 



Piaget, Les Pediculines, 1880, p. 479, pi. xxxix, fig. 1. 



I have taken several specimens of a Menopon from 

 Coots, Grebes, and Loons and from a single Tern, which 

 are referable to this species, or at least to the group of 

 forms of which tridens is the described representative. 

 The descriptions of tridens by Piaget and by Giebel differ 

 positively in various particulars, noticeably in the char- 

 acters of the hairs. My specimens agree exactly with 



