238 MiscellaneoiiK. 



The above-mentioned foundation of the oesophagus is not indicated 

 at all in Ammocoetes. It must not be confounded with the fold which 

 hangs down from the dorsal median line into the branchial cavity 

 of Ammoccetes. 



One of the first processes of the metamorphosis must be the forma- 

 tion of the tongue ; in both my specimens it was already formed, 

 whilst the oesophagus was only permeable for a few millimetres, and 

 the mouth still possessed the narrow opening figui'ed by Yon Siebold 

 (Siisswasserfische von Mitteleuropa, p. 381). — Oherhesslschen Ge- 

 sellsch. fiir Natur- unci HeUkunde, January 11, 1873. 



On the Parasites of the Cetaceans of the N. W. Coast of America, with 

 Descriptions of New Forms. By W. H. Dall, U. S. Coast Survey. 



Among the parasites most widely known as infesting the Cetacea, 

 two classes may be recognized, viz. those which are true parasites, 

 deriving their subsistence from the animal upon which they are 

 found, such as the Pycnogonoids and Cyaml ; and those which are 

 merely sessile upon the animal, and derive no nourishment or other 

 benefit from it which might not equally well be furnished by an 

 inanimate object, such as the various Cirripedes. 



^0 Pycnogonoids have yet been reported from the Cetacea of tliis 

 coast. Brief descriptions of the species of Ci/amiis found upon the 

 California grey, the humpback, and the Arctic bowhead whales 

 were submitted by me to the Academy at a recent meeting. I may 

 here add to those descriptions a few facts since obtained, and bearing 

 upon the species described. I have, through the courtesy of Capt. 

 Scammon, been able to examine a large number of Cyami obtained at 

 Monterey, Cal., from the humpback (Mei/aptcra versahiJis, Cope). 

 They are all of the same species as that (C. sxjfusus) described by me 

 as parasitic upon that whale — a fact which tends to confirm the hypo- 

 thesis that each species of whale has its own peculiar parasites, and 

 that there is rarely more than one species of Cyavnis found upon one 

 animal. The females, which were unknown at the date of my descrip- 

 tion, now prove to resemble the male in every respect, except in re- 

 gard to the sexual organs, and in being a trifle more slender in form. 



Among the Cirripedes, Tuhicindla has not been reported from 

 these waters, nor is the CheJonobia known to have been obtained 

 from any of the whales of this coast. The genera known from the 

 north Pacific waters are Coromtla, an allied form which I believe to 

 be uncharacterized, and Otion or a closely allied form. 



Sessilia. 

 CoRONULA, Lam. 

 Coromda, Lamk. An. s. Vert. v. p. 387. 



Coronula balcenaris, Linn. sp. ; Lamk. Ann. du ITus. i. p. 468, 

 pi. 30. figs. 2-4. 



This species, or one very closely allied to it, was obtained by the 

 late Mr. Bridges, probably from the coast of Central America ; but 

 the identification of the exact locality and the species of cetacean 



