440 M. T. Thorell on the Species of the AvQwYid^e. 



of Milne-Edwards and Baird above cited. It is not impossible 

 that, under the appellation A. foliaceus, two separate species 

 have been confounded. The figures which Vogt * has given of 

 this animal diifFer from the Swedish (and consequently from the 

 genuine) form in having the tail much smaller and almost bent 

 inwards laterally. Jurine and Baird represent the tail such as 

 I have found it in ray own specimens. 



4. A. coregoni, Thor. 

 See page 163. 



5. A. pugettensis, Dana. 



Syn. Argulus pugettensis, Dana, United States' Exploring Expedition, 

 Crustacea, (1853) ii. p. 1351, pi. 94. figg. 2 a et 6. 



Scutum cephalicum oblongum, ellipticum, pedes omnes tegens ; 

 Cauda magna, oblonga, longitudine circa | reliqui corporis, 

 et latitudine j latit. scuti fere sequans, usque ad medium in- 

 cisa, laciniis subacuminatis ; stimulus longus ; sipho sub- 

 clavatus ; cotyledones sat magni, diametro i— ^ corporis lon- 

 gitudinis sequantes; pectinis dentes 3 subconicij dcntes 2 

 inter maxillipedes secundi paris adsunt. — Long, circa 17, 

 latit. 10 millim. ( ? ?). 



Hah. in America boreali (ad oras occid.: ''Puget's Sound"). Hospitium 

 ignotum. 



This very scanty description contains nothing respecting the 

 oral organs ; but the accompanying figures, which seem to be 

 good, and which present the animal both from the dorsal and 

 ventral aspects, show so strong a likeness to the two species im- 

 mediately preceding, that I have not hesitated to place it in the 

 same subdivision of the genus with them. The tail is propor- 

 tionally larger, and especially broader at the base, than in -4, 

 coregoni, 



6. A. catostomi, Dana et Herr. 



Syn. Argulus catostomi, Dana et Herrick, Silliman's Amer. Journ. (1837) 

 xxxi. p. 297. figg. 1-11 ; Milne-Edwards, Hist. Nat. d. Crustaces, 

 iii. p. 445. 



Scutum cephalicum amplum, suborbiculatum, paullo latius quam 

 longius, antice utrinque subsinuatum, pedes quoque ultimi 

 paris ad partem tegens; cauda lata, rotundata, longitudine 

 circa ^ reliqui corporis, postice non usque ad medium incisa, 

 laciniis late rotundatis ; stimulus longus ; sipho ovatus ; coty- 

 ledones mediocres ; pecten plaga media scabra subtriangula, 

 dentibusque 3 late truncatis ; inter maxilhpedes secundi paris 

 dentes nulli. Ramus inferior pedum primi paris articulis 3, 



* hoc. cit. 



