ie deel 
Ney 
Description of the Argulus Catostomi. 297 
Arr. XVIII.— Description of the ARauLus Carostomt, a new pa- 
_ rasttic Crustaceous animal, (with figures.) By J. D. Dana and 
E. C. Herrick, Members of the Yale Nat. Hist. Soc. 
Read before the Yale Nat. Hist. Soc. June 2, and Aug. 4; 1836. 
For our knowledge of the existence of the interesting animal 
which we have attempted to describe in the following paper, we 
are indebted to Mr. Paitos Buaxe of this city. Early in the 
spring of 1835, this gentleman, whom we have always found ready 
to do a service to the cause of science, very kindly brought a spe- 
cimen for our examination. This was accidentally destroyed before 
it had been fully investigated, and nothing further was done concern- 
ing the matter for that year. During the past season however, 
through the attention of the Messrs. Buakes, and of several of the 
intelligent workmen engaged in their establishment, we have been 
liberally supplied. 
A slight examination sufficed to show that the animal was closely 
related to that singular crustaceous parasite, which has attracted so 
much deserved attention, the Argulus foliaceus of Jurine, Jr.* 
The resemblance is so great that a hasty observer might conclude 
that the two are specifically identical ; but after considerable study 
we are convinced that they are not. The correctness of this result, 
we hope to make apparent in the following pages. 
The animal before us has been found at various times in the wa- 
ters of Mill river, near Whitneyville, just below the fall at the man- 
ufactory there established. We have discovered none above the 
fall, but have been told that for a mile above, they are occasionally 
seen. It may not be irrelevant to mention that the tide-water of 
New Haven harbor flows up as far as the fall, so that the stream 
bere has a large admixture of sea-water. It infests the fish here 
called the Sucker. ‘The fish evidently pertains to the genus Catos- 
tomus of Le Sueur, a monograph of which is given by him in the 
Journal of the Academy of Natural Sciences of Philadelphia, Mboe L 
(8vo. 1817.) We cannot satislactorily determine whether it 
C. Bostoniensis or C. communis, and are somewhat inclined to think 
that on further examination hee: may prove varieties of one species. 
et pee ee 
* The elaborate m memoir ‘of 't this duikae dokjiatned in the Annales du Muséum 
@’ Hist. Nat. de Paris, 4to. tome VIL. (1807,) has been our ebief source of infor~ 
mation concerning this species. 
Vou. XXXI.—No. 2. 38 
