36 S. J. /Smith — Crustaceans of the Atlantic Coast. ' 



The chelipeds, in the largest male examined (figure \b), as well as 

 in the females and young, are only slightly unequal and rather slender. 

 The fingers on each hand are about as long as the basal portion of 

 the propodus and their thin prehensible edges are armed with sharp 

 serrations which shut slightly by on the two fingers when the dactylus 

 is closed. The dactylus of the larger cheliped, in all the specimens, 

 has, in addition to the serrations, a small obtuse tubercle near the 

 base. In the only specimen of G. tridens examined (a male consid- 

 erably larger than the largest specimens of 6r. quinquedens) , the 

 chelipeds are more unequal, the larger being proportionally stouter, 

 and the teeth of the prehensile edges of the fingers are more obtiise 

 and the proximal ones even obtusely tuberculiform ; this may be, 

 however, only a character of very old individuals. The sternum, 

 ambulatory legs, and abdomen afibrd no distinctive characters. 



The following are measurements of seven of the nine specimens 

 before me, and also of a specimen of G. trideyis^ from Christiania 



Fiord, Norway, received from Professor G. O. Sars. 



G. tri- 



Carapax. a, $ b, $ f,$ c, 5 /, S <?, S e. S dens 



Length including frontal teeth, 33mm 45 28-7 28*5 25-6 21-7 12-2 56 



Breadth including lateral spines, 45 58 3(5-8 38 33-7 29-1 16-7 75 



Ratio of length to breadth, 1:1-36 1:1-29 1:1-28 1:1-33 1:1-32 1:1-34 1:1-37 1:1-34 



Breadth in front of lateral spines, 39 51-8 32-5 32-3 29-2 24-4 13-8 64 



Ratio of length to this breadth, 1:1-18 l:l-]5 1:1-13 1:1-13 1:1-14 1:1-13 1:1-13 1:1-14 



Length of posterior legs, 95 57 52 50 39 24 115 



This very interesting species was first known to me, about ten 

 years ago, from two specimens, in the collection of the Portland 

 Society of Natural History, obtained by Mr. C B. Fuller from 

 stomachs of fishes taken in deep water olf Casco Bay. These speci- 

 mens were somewhat shrunken from partial digestion, immersion in 

 alcohol and subsequent drying, and the measurements (given above 

 in column a) of the smaller one of the two may be slightly incorrect. 

 The other specimens which I have examined were all taken in deep 

 water in the Gulf of Maine, ofif Massachusetts Bay, The largest two 

 of these {b and c) Avere obtained, August 19, 1877, by Professor 

 Verrill and party of the United States Fish Commission on board the 

 " Speedwell," at 160 fathoms, soft muddy bottom, about forty miles 

 east of Cape Ann, latitude 42° 38' north, longitude 69° 38' east. 

 Two others were dredged off Massachusetts Bay by Professor Packard, 

 while on board the "Bache" in September, 1873: a female {d), 

 carrying an abundance of eggs, in latitude 42° 18' north, longitude 

 69° 49' east, 142 fathoms, soft blue mud ; and a A^ery small female 

 (e), latitude 42° 20' north, longitude 70° east, 117 fathoms, on a bot- 



