722 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxv. 



ARGULUS ELONGATUS Heller. 

 Plate XXII, fig. 61. 



Arguhis elongalus Het.ler, Beitriige zur Kenntniss der Siphonostomen. Sitzungsb. 

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

 RELL, Om tvenna Europeiska Argulider, etc., ffifvers. af Kongl. Vetensk.- 

 Akad. Forhandlingar, 21st series, Stockholm, 1864. 



Carapace very short, triangular, wholly without lobes; no posterior 

 sinus. Abdomen one-quarter the length of the rest of the body, 

 longer than wide; anal sinus broad triangular, cut almost to the very 

 base, lobes divergent, acuminate-lanceolate; papillai basal. Sucking 

 disks medium size, placed well forward; posterior maxillipeds good 

 size; basal plate without teeth but well armed otherwise. Antenna 

 of normal size and armament. As there are no carapace lobes the 

 swimming legs are left wholly uncovered. No data as to iiagella or 

 oviduct papillffi, but inasmuch as Heller has been careful to put in the 

 Iiagella in the other species he has illustrated, the absence of them in 

 his figure of elongatus indicates that he could not find any. Color a 

 3^ellowish white, very darkly pigmented and speckled; bases of the 

 swimming legs also with circular black spots. 



Length 10 mm.; length of carapace 4.3 mm.; breadth of carapace 

 G umi. ; length of al)domen 2 mm.; breadth 1.1) mm. Male unknown. 



The abrupt truncation of the carapace distinguishes this species at 

 once from all others. 



Habitat. — Brazil. Host unknown. 



{Elongatus = alludes to the elongated appearance of the body, due to 

 the absence of lobes on the carapace — i. e., the elongation is apparent 

 not real.) 



ARGULUS FOLIACEUS Linnaeus. 

 Plate XXIV, fig. 69. 



Port des Poissons Baldner's manuscript, 1666. 

 Monoculus Cauda foUacea plana Loefling, 1750. 

 Pou de Gasteroste, Pou de la carpe Baker, 1753. 

 Monculus foliaceus Linn^us, 1758 and 1761. 

 Monoculus piscinus Linnaeus, 1761. 

 B'mociUus ganterosteus Geoffroy-Saint Hilaire, 1762. 

 Insectum aquatium Ledermuller, 1764. 

 Argiihis i-hnrmi MUller, 1785. 

 Arguing ^Jr/plilinis iMiJLLER, 1785. 

 Moiiiiciiliis iirijiiInK Fabricius, 1792-1794. 

 Mut'iH'ithis </iirini CuviER, 1798. 

 Oz(jln.'< ga.'<lrr<istrl Latkeille, 1802. 



Argidus foliaceus Jurine, 1806. [This name retained l)y the various authors given 

 in the historical part, which see.] 



Carapace elliptical, longer than wide; posterior sinus narrow, ex- 

 tending two-fifths the length of the carapace. 



Abdomen one-fourth the length of the rest of the body, al^out as 



