142 SMITHSONIAN MISC]iLLANE;OUS COLLEICTIONS 



not protruded. Outer maxillipeds pilose, hairs plumose ; palpus 

 short; penult joint with extremity almost pointed; dactylus minute, 

 joined at about the middle of the penult joint. Ambulatory feet of 

 the third pair longest ; dactyli of the first and second pairs short,- 

 equal ; those of the third pair very long and tapering to a fine point ; 

 those of the last pair also long. Dimensions of the carapax : Length, 

 0.168; breadth, 0.21 1 inch. 



Found in small oysters from the rocks at the Bonin Islands. 



236. PINNOTHERES PARVULUS Stimpson 



Pinnotheres parvulus Stimpson, Proc. Acad. Nat. Sci. Phila., x, p. 108 

 [54], 1858. 



Description of the female : Carapax narrower than in P. pisum; 

 front nearly the same as in the female of that species. Outer max- 

 illipeds rather hairy ; exognath, excluding its palp, a little less than 

 half as long as the meros-joint of the endognath ; penult joint of en- 

 dognath twice as long as carpus ; dactylus slender, reaching to the 

 extremity of the penult joint. Ambulatory feet toward extremities 

 hairy ; those of the last two pairs longer than the first two, and with 

 proportionally longer dactyli. Length of the carapax, 0.14 inch. 



A specimen of this species was found in each and every example 

 of the small bivalve Mcroc quadrata, of which several were dredged 

 from a sandy bottom in twenty-six fathoms, in the China Sea, at 

 about latitude 23° N. 



Genus PINNIXA White 



The best known species of this very distinct genus are natives of 

 the American coast, but they will undoubtedly be found to be numer- 

 ous at the proper latitudes in all parts of the globe, when sought for 

 in their peculiar lurking places. They are parasitic in their habits, 

 like the Pinnotheres, which they so much resemble in the structure 

 of their jaw-feet; but in place of living with the bivalve mollusk in 

 his shell, they prefer the society of marine worms and worm-like 

 Holothuridse, in the tubes or holes of which they are generally found. 

 In their transversely elongated shape they are well adapted for 

 slipping about in such cavities. One South Carolinian species 

 lives in the tubes of Chcctopterns, another in the hole of the large 

 Arenicola, and the larger of the expedition species was found in the 

 hole of a Caudina. 



The Pinnothera faba of Dana is intermediate in its characters 

 between Pinnotheres and Pinnixa, but has the maxillipeds of the 



