228 CORYSTOID CRABS—BENEDICT. | 
Telmessus acutidens (Stimpson). 
Plate xxvi, fig. 1. 
Cheiragonus acutidens Stimpson, Proc. Acad. Nat. Sci. Phila., p. 40, 1858. 
Telmessus acutidens Miers, Proc. Zodl. Soc. of London, for 1879, p. 36. 
Telmessus acutidens S. I. Smith, Geol. Survey of Canada, Report for 1878~79, p. 208 
B, 1880. 
The collection contains one male specimen from 8 fathoms, mud bot- 
ay 
tom, Yokohama, taken by the U. 8.5. Tuscarora (3388); and 14 males, 
8 females, from Japan, H. Loomis (16275). 
This species can easily be distinguished from 7. cheiragonus by the 
much more slender lateral spines, and by the spine at the posterior base 
of the long spine, making three postero-lateral spines, while cheiragonus 
has but two. Its outline is not so angular, and it is much more convex 
than the preceding species. The point of the long lateral spine curves 
forward but little, while that of cheiragonus curves so much that it is 
naturally counted with the denticles on its anterior edge and base. 
Not counting the terminal point these denticles number four in cheir. 
agonus and five in acutidens. 
The following description of Telmessus acutidens is from Dr. Stimp- 
son’s unpublished report upon the Crustacea of the North Pacific Ex- 
ploring Expedition: (The latin description was printed under the name 
Cheiragonus acutidens Stimpson in Proce. Nat. Sci. Phila., p. 40, 1858.) 
‘‘Carapax rather narrow; proportion of length to distance between 
tips of lateral teeth, 1:1.26. Surface covered with setiferous tubercles, 
mostly transverse, as in other species of the genus. Lateral teeth slen- 
der, sharp, the principal or middle one very long; a small intermedi- 
ate tooth at the base of the principal one behind. Between the teeth 
and sometimes on their edges there are a few small spiniform denticles. 
Interantennal front or rostrum with a deep median sinus, and a smaller 
sinus or excavation at the tip of each fork, as in C. hippocarcinoides. 
Antenna more than one-third as long as the carapax. Feet all squam- 
ose or scabrous and setose. Chelopoda somewhat spinous above; 
hand costate externally, the costw sharply tuberculated. 
‘“‘Color in life light brick-red above; paler, inclining to yellowish below. 
Some specimens are of an orange color, but always dusky. Pincers 
dark brown. Dimensions of amale: Length of carapax, 1.45; breadth 
between tips of lateral teeth, 1.83 inch. It grows to a length of 3 
inches, but the larger specimens, of which several were collected, were 
accidentally lost. 
“It may be distinguished from C. hippocarcinoides as found on the west 
coast of America, as well as from Telmessus serratus, White, by the 
greater length and acuteness of the lateral teeth, particularly the larger 
one; also by the existence of a small intermediate tooth behind the 
large one.” 
This crab is very common in the Bay of Hakodadi, in northern 
