NEW-YORK FAUNA — CRUSTACEA. 



LlBINIA CANALICULATA. 



PLATE IV. FIGURE. 



(STATE COLLECTION.) 



Libinia emarginata? Leach, Zoological Miscellany, Vol.2, p. 130, pi. 108, 



L. canaltculata. Say, Jour. Acad. Nat. Sc. Vol. 1, p. 77, pi. 4, fig. 1. 



It. emarginata. Desmarest, Consul. g£n£rales, p. 162. 



L. cannclee, L. caniculata. Edwards, Hist. Nat. des Crust. Vol. 1, p. 300. 



L. douteuse, L dubia. Id. lb. pi. 14, fig. 2. 



L. emarginata. Gould, Inrertebrata of Mass. p. 328. 



Description. Shield globular-pyriform, densely hairy, and usually coated with a thick 

 greenish brown sordes. Rostrum produced, deeply notched at the tip, convex above, con- 

 cave beneath. Orbits rounded, with a stout spine on the antero-superior border and a smaller 

 one beneath, with an intermediate fissure above and beneath. The shield is impressed above 

 by two deep parallel curvilinear furrows, approaching each other about the middle, then 

 diverging, forming an intermediate oval area, and ultimately approaching each other on the 

 posterior portion of the shield ; in front, these furrows curve behind the orbital processes, 

 and terminate at the base of the rostrum. A transverse series of four to six small spinous 

 tubercles across the anterior part of the shield ; several others irregularly distributed over the 

 upper surface. Feet long, covered with short dense hair, the second and third pair rather 

 longest, the others successively shorter. Hands sub-cylindrical, sub-compressed, linear. 

 Fingers half as long as the hand, with from twelve to fifteen irregular obtuse teeth, and an 

 impressed lateral line becoming effaced towards the tips. Nails acute, polished, with an im- 

 pressed line on each side. 



Color, soiled greenish or brownish. Hands and fingers reddish white at the tips. 



Length of shield, 3«0. Transverse diameter, 2*4. 



Length of anterior pair of feet, 5 - l ; of the succeeding pair, 5*5. 



These dimensions are taken from a specimen of the average adult size. Younger indivi- 

 duals 1 "4 in length are more pyrifom in shape, are entirely covered with a dense downy hair, 

 and the spine not so prominent as in the adult. In this state I suppose it to be the L. dubia 

 of Edwards, which he characterises by " the second pair of feet one and a fourth of the 

 length of the shield, but much longer than the first pair ;" while to the L. canaliculata he as- 

 signs the character of " the second pair one and a half the length of the shield, and slightly 

 longer than the first pair of the male." The emarginata of Leach, referred to above, is pro- 

 bably identical with the canaliculata ; and the name, on the score of priority, should have 

 been retained, had the description been sufficiently detailed. 



The Sea-spider, or Spider Crab, is very common on the coast of this State, and it has 

 been observed from the Chesapeake northwardly, but its precise geographical limits are not 

 known. It is not used as food, but I am assured that it is well flavored, particularly the fe- 

 male. Occasionally they are taken with the seine in such quantities as to be used as manure. 

 Their usual places of resort are on oyster beds, where they are thought to commit great 

 ravages by destroying the young spawn of the oyster. 



