THE CRUSTACEA OF NEW JERSEY. 135 



aa. Carapace orbicular, wider than long; color variegated and brilliant; in 

 males carapace lobes just reach base of abdomen, anterior swimming-legs 

 with flagella, and abdomen broadly triangular ; in females carapace lobes 

 not reaching abdomen, anterior swimming-legs with full-sized flagella, 

 and oval abdomen "medium. versicolor 



Argulus alosae Gould. 



Plate 36. 



Herring Louse. 



Argulus alosoc Gould, Rep. Invert. Mass., 1841, p. 340, fig. (On gills of "ale- 

 wife Alosa vulgaris") Massachusetts. 



R. Rathbun, Proc. U. S. Nat. Mus., 1884, p. 485. Great Egg Harbor, 



New Jersey. 



Wilson, Proc. U. S. Nat. Mus., 1903, p. 707, PI. 12, PI. 26, fig. So. 



Great Egg Harbor, New Jersey. Patchogue, Long Island. 



Description. — Carapace elliptical, longer than wide. Antero- 

 lateral sinus shallow, often becomes deep and sharp on shrink- 

 ing in alcohol, so that cephalic area protrudes in sort of semi- 

 circle. Posterior sinus rather narrow, about one-third length 

 of carapace, three tmies long as wide, and lobes well rounded. 

 Sucking-disks large, about one-fifth width of carapace. Poste- 

 rior maxillipeds medium, with triangular basal plate armed with 

 three short blunt teeth and strongly papillated. A'ntennae small 

 and armed with rather weak spines and hooks. Body projects 

 considerably beyond carapace, with thoracic segments long and 

 wide, and posterior one projects over abdomen as well-rounded 

 lobe on either side with shallow sinus between. Abdomen broad 

 and long, more than one-third length of rest of body, with well- 

 rounded lateral margins. Anal sinus broad, triangular, cut to 

 center, leaving two lobes sharply pointed and flaring slightly at 

 their tips, papillae small and basal. Swimming-legs long, pro- 

 jecting far beyond carapace, and lobes on basal joints of poste- 

 rior pair small and rectangular. Abdomen in male very much 

 longer, but no modifications of legs except regular peg and 

 semen vesicle. No flagella. Color yellowish-white, mottled 

 along carapace lobes with brown. Some measure 12 by 6 mm. 



(C. B. Wilson.) 



