ACADEMY OF SCIENCES. 301 



Ion. terga .07 in.; lat. do. .07 in. Color of membranes, when living, sulphur 

 yellow ; hood extremely protrusile. 



This species is found sessile on the California Gray whale {Rhacliianectes slnv 

 cus, Cope). I have observed them on specimens of that species hauled up on 

 the beach at Monterey for cutting off the blubber, in the bay whaling off that 

 locality. The superior surface of the lateral lamina? being covered by the black 

 skin of the whale, are not visible ; and the animal removed from its native cle- 

 ment — protruding its bright yellow hood in every direction, to a surprising dis- 

 tance, as if gasping for breath — presented a truly singular appearance. 



PEDUNCULATA. 



Otion, Leach. 

 Otion, Leach. Ency. Brittanica, suppl. vol. iii, p. 170. 



Otion Stimpsoni, Dall. 



Scuta only present, beaked, with the umbones on the occludent margins ; an- 

 terior prolongation the longer, pointed, rather slender ; posterior prolongation 

 rounded, wider; external margin concave; color, (in spirits) light orange with 

 a dark purple streak on the rostral surface and on each side of the peduncle ; 

 while the lateral surfaces of the body case and lobes are mottled with dark pur- 

 ple. The lower lip of the orifice is transversely striated and translucent, the 

 upper margins, slightly reflexed internally, white ; in some specimens with two 

 prolongations or small lobes above, which are wanting in other specimens. The 

 tubular prolongations, very irregular and variable in size and form, usually unsym- 

 metrical ; one sometimes nearly abortive. Length of peduncle, 2.8 in.; of body, 

 2.16 in.; of lobes, 2.0 in.; of orifice, 1.18 in.; of scuta, .55 in.; width of scuta, 

 • 16 in. 



Habitat : on the " Humpback " (M. versabilis) sessile on the Coronxdai. 

 which infest that species, but never, so far as I have observed, on the surface of 

 the whale itself. 



Dr. Leach describes five calcareous pieces, namely, the scuta, terga and ros- 

 trum in the typical species, (0. Cuvieri, Leach) and they are figured by Reeve ; 

 but this species has certainly only the scuta. Whether this difference is of more 

 than specific value I am not able to decide, owing to the great paucity of works 

 of reference here. I should be unwilling to describe the species, were it not 

 that it was submitted to the late lamented Dr. Stimpson for examination, and 

 was pronounced by him to be new. 



A variety, or perhaps another form, was observed by me in Bering Strait, in 

 1865, which was blotched all over with rose pink, and had the scuta narrower 

 and more slender ; it was also smaller than the specimens before me ; but as it 

 is not at hand, I am unable to decide with certainty. 



I am indebted to Capt. C. M. Scammon and R. E. 0. Stearns, Esq., for 

 specimens and facilities furnished in the preparation of this paper. Most of 

 the specimens were collected by the former gentleman, and will be figured in his 

 forthcoming monograph of the cetaceans of the N. W. Coast. 



Pkoc. Cal. Acad. Sci., Vol. IV.— 22. January, 1873. 



