4 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 
Measurements in millimeters. 
Station— 
| 
1032. 939. 1113. | 1154. 
DOSE eek abe emehen ase kbaw stem fase Geer Gest ee nee ches penne Rep emnee eter Young. ron rom 
Length of carapax, including rostral and posterior spines --.---.----. 15.5 21.5 26.3 53. 5 
Length of earapax from base of rostral to tip of posterior spines..--| 10.0 14.0 18.0 42.5 
Length of carapax, excluding rostral and posterior spines..... . pee 9.1 12.1 16.5 40.5 
envth of rostral horns OL Splines) .~. ee .cos-= cesses epee ccscueeasens 5.7 8.0 9.0 12.0 
Breadth of carapax, including lateral spines. ....-...--.-.-.---.----- ie 16.0 19.5 39.5 
Breadth of carapay, excluding lateral spines .......----..... Saba ee 6.8 9.0 12:8 32.0 
Menethiot branchiauanine! -.2-5-..s =e soso seh one jase ae eee nee eet 3.1 4.8 5. 2 6.0 
I Gyaverdn ere Cle etl Ges ee Ri ee a SS ae oe ie 11.0 15.0) 21.5 62.0 
Length of chela.....-.-...0.00 25-3 - ec ccns os sececenccceeccesscene== 4.6 6.4, 10.0 28.5 
Te} euiihiln Ghie ONCE BR Bara ne sos aoe mc Seto Ge 9 O00 NO OS soN ese g bode 09 1.3 1.6 4.0 
Lbpepy tide OE RPE ABO Se Hae cogsesnonordccaonnd SspASscesce Geeaseac 2.0 2.5) |. ano 5.4 
Lenrthior tirstambulatory log cn. sce cee enna som amen pees iss 18.0 25.0 37..0' |uocameee 
TBH OTNOL GACtYAUS) “se -)6 sation pac ose ene ac Seen een: ote ee oes ante ait 3.5 4.0 a fd Pee 
Leéneth of second ambulatory leg... obi se -eocccwebesaciecduscasaey = 15.0 22.5 31.5 95.0 
ene th Ob GAOL LUG ree. amitelacelseenaeleeiee eae ees iae eee eee eels 3. 2 4.8 | 6.0 17.5 
Amathia Tanneri, sp. nov. 
Allied to the last species, but readily distinguished from it by the 
narrower carapax with longer and less diverging rostral horns and fewer 
and more nearly equal spines, and by having a single spine only on the 
base of the antenna. 
Male.—The carapax, excluding the rostral horns and the spines, is 
about as broad as long. The rostral horns are nearly straight, much 
less divergent than in A. Agassizii, and, in the larger of the two speci- 
mens seen, much more than half as long as the rest of the carapax. 
The supraorbital spine and the postorbital processare as in A. Agassizii, 
but the basal segment of the antenna is unarmed except by a single 
spine at the distal end. There are four long and approximately equi- 
distant spines on the mesial line of the carapax, the two anterior on the 
gastric region and smaller than the others, which are on the cardiac 
region, the posterior being near the posterior margin and projecting 
slightly backward over it. There are no prominent spines on the gas- 
trie region except the two median, but there is a minute tubercle or ru- 
dimentary spine either side about equidistant from the two median, and 
on the cardiac region there are no spines or tubercles whatever except 
the two median. There is a single long hepatic and a great branchial 
spine, as in A. Agassizii, but there are no other spines or tubercles on 
the branchial region except two, about as long as the cardiac spines, and 
about equidistant from each other and from the great branchial, the 
posterior gastric, and the anterior cardiac. The anterior angle of the 
buceal area projects in a dentiform process either side, as in A. Agassizii, 
and back of this the prominent margin of the pleural region is armed 
with three small tubercles or rudimentary spines. There are no spines 
or tubercles on the side of the branchial region above the basis of the 
cheliped and first ambulatory leg, and no tubercles whatever on the 
postero-lateral margins. 
The chelipeds and ambulatory legs are essentially asin A. Agassizii. 
