238 Miscellaneous. 



The above-mentioned foundation of the oesophagus is not indicated 

 at all in Ammocoefes. 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 figured by Yon Siebold 

 (Siisswasserfische von Mittclenropa, p. 381), — OberhessiscJien Ge- 

 sellsch. fur Natur- unci HeUlcunde, January 11, 1873. 



On £ke 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 Cetaeea, 

 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 Cycimi ; 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. 



No Pvcnogonoids have yet been reported from the Cetacca of this 

 coast. Brief descriptions of the species of Gijamus 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 (Merjaptera versahilis, Cope). 

 They are aU of the same species as that (C. suffiisus) 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 Cyamvs found upon one 

 animal. The females, which were unknown at the date of mj 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, TuhicineJla has not been reported from 

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

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

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

 be uncharacterized, and Otlon or a closely allied form. 



Sessilia. 

 CoEONULA, Lam. 

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



Coromda balmnaris, Linn. sp. ; Lamk. Ann. du Mus. i. p. 468, 

 pL 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 



