Dec, 1902. Carriker : New Mallophaga. 229 



darker, quadrilateral spot on each side of the median line, not touching the posterior 

 margin of the segment, and each, in the first three segments, containing a still darker 

 crescent-shaped band opening outward ; in segments four to six, a median, transverse, 

 blackish-brown band, widening laterally to the width of the segments ; eighth seg- 

 ment with a median dusky spot and the lateral band extending inwardly along the 

 posterior margin ; ninth segment almost completely blackish-brown, with a small 

 median, terminal emargination and two hairs on each side ; the genital hooks are 

 rather small, extending from the posterior margin of the sixth to the posterior margin 

 of the eighth segment. 



The female differs considerably from the male, especially in the markings of the 

 abdomen. The abdomen is without the marked constriction posteriorly, widest at the 

 third segment ; without the median bands on segments four to six ; the legs are 

 stouter ; the sixth and seventh segments of the abdomen have a continuous median 

 blotch, while the ninth is more pointed and clear in the median portion ; the lateral 

 bands of the eighth segment are very narrow. Measurements as follows : 



Body, length 3.65 mm., width .72 mm. ; head, length .77 mm., width .65 mm. 



Five males and one female collected from a Canvasback Duck 

 {Aythya val/isnena), shot at Lincoln, Neb., March 25, 1901. Piaget's 

 bifasciatus resembles this new form more than any other species of the 

 genus, but it differs in the shape of the abdomen and thorax and in 

 the abdominal markings. 



EXPLANATION OF PLATES. 

 Plate XX. 

 Fig. I. Docopho7-us cephahntts, sp. nov. (9-) 

 Fig. 2. Nirmus trimarginis, sp. nov. ( 9 • ) 

 Fig. 3. A'irmus infreqitens, sp. nov. ( J ). 

 Fig. 4. Nirnuis tiitncaitis, var. niagnocepliahis, var. nov. ( J ). 



Pl.vte XXL 

 Fig. I. Nirniits hioceUatns var. nigropicttis, var. nov. ( 9 )• 

 Fig. 2. A^irmus angusti/rons, sp. nov. ( 9 )• 

 Fig. 3. T}'ino/on conspurcatuvi Nitz. ( 9 )• 

 Fig. 4. Colpocephaluni qtiadrimactilaius , sp. nov. ( ^ ). 

 Fig. 5- Nirmus trimarginis, sp. nov. ( ^ ). 



Plate XX 1L 

 Fig. I. Akidoproctiis kelloggi, sp. nov. ((J). 

 Fig. 2. Akidopmctiis kelloggi ( 9 )■ 

 Fig. 3. Physostomnm picturatus, sp. nov. ( 9)- 

 Fig. 4. Nitz»chia pulicaris var. tibialis, var. nov. ( <J ) . 

 Fig. 5. Nitzsckia pulica7-is var. tibialis ( 9 )• 



