408 Miscellaneous. 



development of the ova. Posterior part of the body as in C. Scam- 

 moni, but there are no serrations on the anterior edge of the seventh 

 segment. Length of largest specimen 0-8 inch. 



Domicile on Balcena Sieboldii, Gray ; North Pacific Ocean. 



This is readily distinguished from C. mysticeti, Dall, by its spiked 

 " hands " and knobby branchial segments, and from C. Scammoni 

 by its straight unequal branchiae, long antennae, knobs, and the shape 

 of the head. 



Cyamus gracilis, n. sp. 



This species is of a pale waxen yellow, of elongated and slender 

 form, and small and slender limbs. It more nearly resembles C. 

 suffasus, Dair(Scammon, loc. cit. pi. x. fig. 3), than any of the other 

 described species. It differs from that species in the following par- 

 ticulars •, — It is smaller, the largest si^ecimen measuring only 0-5 of 

 an inch in length. It wants the purple colour, and is more compact 

 and solid. The second pair of antennae are much shorter, being only 

 eqnal to the first segment and half of the next segment of the cor- 

 responding members in C. sujfusus. The branchiae, though similar, 

 are proportionally one third shorter. The posterior limbs are 

 shorter and much more weak and slender than in C. suffitsus. The 

 first pair of " hands " are slenderly pyriform instead of quadrate ; 

 the second pair are simple, without the tubercles between the 

 articulation of the limb and the " finger ; " or, at most, in the largest 

 specimens the termination of the hand under the articulation of the 

 hook or finger is slightly produced into a point. The head is shorter, 

 subtriangular, instead of elongated. Lastly the segments of the body 

 are more or less closely appressed against each other before and be- 

 hind, instead of being laterally attenuated and separated as in G. 

 si(ffusiis ; they are also proportionally less wide from side to side 

 than in C. suffusus. 



Habitat, with the last. 



The prominent features of this species are its slender and compact 

 form, short antennae, and weak and inconspicuous posterior limbs. 



Captain T. W. Williams brought down from the Arctic Ocean in 

 1873 some parasites from the walrus, which he presented to the 

 Academy. These parasites are of a very dark brown colour, almost 

 perfectly round in shape, with an indistinctly segmented abdomen 

 somewhat roughened with short hairs, three pairs of short bristly 

 legs, a distinct but small throat, and very small and short head. 

 There is one pair of short stout antennae with four joints ; the mouth 

 is suctorial. There are no other appendages to the abdomen or head. 

 The want of books of reference prevents my being able to refer these 

 creatures to their proper generic position ; and it would be, in any 

 case, unadvisable to describe them as new, as parasites from the 

 walrus of the North Sea have recently been described by a Swedish 

 naturalist, and they may be identical with the present form. — Pro- 

 ceedings of the California Academy of Sciences, March 3, 1874. 



