720 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxv. 



distinguished. The non-American species of the family will be treated 

 very briefly and from a purely systematic standpoint, after first 

 describing the four from Central and South America. 



ARGULUS NATTERERI Kollar. 

 Plate XXII, fig. 63. 



Argulus naUereri Heller, Beitriige zur Kenntniss der Siphonostomen. Sitzungsb. 

 d. kais. Akad. d. Wissensch., Math.-naturwissensch. CL, XXV, 1857. — 

 Kroyer, Bidragtil Kundskab om Snyltekrebsene. Naturhist. Tidskr., 3die 

 Rsekke, 2 Bind, 1863. — Thorell, Om tvenna Europeiske Argulider, etc. 

 Gi^fvers. af Kongl.-Vetenyk. Akad. Forhandlingar, 2l8t series, Stockholm, 

 1864. 



Carapace orbicular, wider than long; posterior sinus narrow, reach- 

 ing nearly half the length of the carapace. 



Abdomen relativeh^ the smallest of any species, not more than one- 

 tenth the rest of the body, wider than long; anal sinus narrow, cut 

 scarcely to the center; papilhe basal. 



Sucking disks large, placed well back in the carapace, veiy close 

 together, equaling about one-fourth the width of the carapace; poste- 

 rior maxillipeds small and w^eak; basid plate narrow triangular with 

 an al)rupt angle near its center; teeth long and sharp with an accessory 

 spur at the base of the outer one. 



Antennte large and well armed. Swimming legs very short, none 

 of them reaching the edge of the carapace; lobes on both joints of 

 the posterior ones flap-like and covered with seto3. Flagella present; 

 no papilUc at the opening of the oviduct. 



Length 12 mm.; length of carapace 11.5 mm.; breadth of carapace 

 13 mm.; length of abdomen 1.2 mm.; breadth 2 mm. Male unknown. 



Color grayish white; skin covered with warts and spines on the dor- 

 sal surface. Two dark oblique spots on the abdomen. 



Ilahitat. — Brazil, South America, on the skin and in the gill cavity 

 of Sahno (Hydrocyon) hrevidens Cuvier. 



(Named for Johann Natterer, who obtained these Brazilian Arguli 

 together with the specimens of the genus Dolops.) 



ARGULUS SALMINI Kroyer. 



Plate XXII, fig 64. 



Argulus salminl Kroyer, Bidrag til Kundskab om Snyltekrebsene. Natnrhist 

 Tidskr., 3die Rjekke, 2 Bind, 1863. — Thorell, Om tvenna Europeiski 

 Argulider, etc. Gilfvers. af Kongl. Vetensk.-Akad. Forhandlingar, 21st 

 series, Stockholm, 1864. 



Carapace orbicular, wider than long; posterior sinus ^vide, one-fourth 

 the length of the carapace, cephalic area prominent. 



Abdomen very small, about one-sixth the rest of the body, wider 

 than long; anal sinus narrow, not cut to the center, lobes broadly 

 rounded; papilla basal. 



