704: PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxv. 



36. Carapace entirely covering the feet; abdomen larger, 0.33;^ broadly orbicular; 



color green, marbled with blue striata, p. 735 



37. Carapace narrowed anteriorly, not covering the feet; abdomen still larger, 0.4, 



broadly triangular; color a uniform dark green repni((, p. 734 



A^. Carapace lobes just reaching the base of the abdomen. 

 B. Carapace elliptical, longer than wide. 



C. No spines on the ventral surface; swinnning feet reaching well beyond the 

 edge of the carapace. 



38. Carapace wider anteriorly; abdomen 0.5; anal sinus narrow, diamond-shaped, 



with the papillje in the angles of the diamond; testes three-lobed. 



ranarum, p. 737 



39. Carapace wider a little behind the center; abdomen 0.65; anal sinus triangular; 



lobes widely divergent, acuminate; papillte basal; testes two-lobed. 



gcaiji, p. 736 

 A^\ Carapace lobes not reaching the abdomen. 

 B. Carapace orbicular, wider than long. 

 C. Abdomen cut almost to the base; no spines on the ventral surface of the 

 carapace. 



40. Abdomen medium, 0.33; lobes widely divergent and acute doradis, p. 733 



41. Alidomen very long, 1-5 to 2; lobes nearly parallel and acuminate. 



longicauda, p. 732 

 C^. Abdomen cut less than one-half; ventral surface well armed with spines. 



42. Abdomen short, 0.27, orbicular; basal plate of maxillipeds with only two 



teeth bidentata, p. 736 



No figure of Argulus africanus, irtdicits^japonicus, or sciitiformis, 

 or Clumopeltin hiennla^ has ever been published. 



ARGULUS MuUer. 



The genus possesses the same characteristics as the family and is 

 distinguished f I'om other genera by the presence of a sheathed stylet 

 or sting in front of the mouth, used for a piercing organ. The ante- 

 rior maxillipeds are transformed into sucking disks, Avhile the poste- 

 rior ones are armed with sette, spines, and a chitinous plate upon their 

 basal joint. 



This plate is elevated above the surrounding surface and roughened 

 by spines or warts, and is prolonged into three sharp spines on its 

 posterior border. There are two pairs of antennae, the anterior of 

 which are armed with stout sickle-shaped hooks and function as organs 

 of prehension. The basal joints of the posterior swimming legs are 

 usually prolonged into lobes projecting beneath the abdomen. 



ARGULUS LATUS Smith. 



Plate IX. 



Argulm Intiis Smith, Invertebrate Animals of Vineyard Sound, Report of IT. S. 

 Com. Fish and Fisheries, 1872. — Rathbun, Annotated List of Parasitic 

 Copepoda, Proc. U. S. National Museum, VII, 1884. 



Carapace orbicular, wider than long; posterior sinus about one-fifth 

 the length of the carapace, as wide as long; abdomen a third as long as 

 the carapace, two-thirds as broad as long, the lateral margins slightly 

 curved and nearly parallel; anal sinus very broad, about one-third the 



