DESCRIPTIONS AND DETERMINATIONS OF SPECIES 5 1 



segments with numerous short, stout spines, and with a transverse row 

 of slender hairs along the posterior margin. Succeeding segments with 

 a diminishing number of hairs and spines, these being replaced by small, 

 thin scales, particularly along the lateral margins. 



Ventral side thickly beset with short, stout spines, and with no scales 

 except on the seventh and eighth segments, where the spines are almost 

 entirely replaced by scales. Ninth segment and the posterior margin of 

 the eighth with a great number of long, slender hairs. 



Description of the Male. — Total length 2.4 mm., length of head 

 .5 mm., length of abdomen 1.55 mm., width of head .4 mm., width of 

 thorax .5 mm., width of abdomen 1.00 mm. 



Closely resembling the female, except for the slightly more pointed 

 abdomen. Ventrally almost entirely free from scales. Basal plate broad, 

 more heavily chitinized at the margins than elsewhere. Parameres very 

 short and slender. Penis large and bluntly pointed. 



Genus ECHINOPHTHIRIUS Enderlein. 



Echinophthirius Giebel, Zeitschr. fur Ges. Naturw., vol. 37, p. 177, (1871). 



Echinophthirius Enderlein, Zool. Anz., vol. 29, p. 661, (1906). 



Echinophthirius Enderlein, Deutsche Siidpolar Exped., vol. 10, pt. 4, p. 507, (1909). 



Antennae four-segmented. Body entirely without scales. Head, 

 thorax and abdomen beset with long, heavy spines. 



Echinophthirius phocae (Lucas). 



Reported by Osborn, as E. setosus, from harbor seals in the New 

 York Aquarium. 



In addition Echinophthirius groenlandicus (Becher), host Phoca 

 groenlandica, and Echinophthirius sericeiis Meinert, have been reported 

 from Greenland. 



