54 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. . 
Three specimens from station 941 give the following measurements 
in millimeters: 
1 2. 3 
Sex .---------------- +--+ =< eee ne ne ee ee eee ee en cee ene ee eee eee cS i 
Length, tip of rostrum to tip of telson. --. ee eee eee eee ewe ween = om 22. 0 17.5 17.5 
Length of carapax, including rostrum... ..-...--------.-2ss---eeen---eene -=-- 12.2 9.4 9.3 
Length of rostrum ..-.-.---.----------. --- 2 o-oo een conn cen ween == =e 3.0 2.3 2.2 
Breadthiof carapax.at anterior ancless-seeca. = anmem ae mcie= ama teaaaenin= =e =e 7.0 5.4 Ba 
Greatest breadth Of Carapax= coe o- os ae ooo a ene ose nemesis ann scent === 9.0 7.3 7.0 
Mencibvot Cheliped ernest see= = seine een ae eee eee et al eae anteater eee 35. 0 31.0 28.0 
ee Uy OF TAO GUS ieee se ta ante ae mm a ie alee mee 12.0 11.0 10.0 
IEC ilo meNy Se See a eRe Sse ee Soe so sore ss sseaosehe. Sse 5.0 4.3 3.8 
Ib iiya di Wid (Ns) Css Sao Eis eee eecocan Sg mech ae epeoseisooseos Sooo. asos 15.9 13.3 11.5 
Greatest breadth of chelavrnse=-sce ace ana- eee een = be her aeaae aiee ee eae er aee ate 4.0. 2.1 1.3 
Length of dactylus..--.-. 2-0. 22.22 + ~~ eon ce ename win weenie senna n= ceneennencnn== 6.5 5.2 4.6 
ensthohmirsiam bolatony lem sib eee =e eee eee nee een eee niet 22. 0 19.0 BYES) 
Wen ob Of belSOW eee omic <= 2 6 op mae ae ee eel ae ae ae me ee 3.3 2.5 2.5 
IBTeN Oth OL teISOU ee ee sete salar eleln < eleatelee ae mo ll Sa eae 4.5 3.6 3.5 
Diameter Of CY © .- 2.22 2 -- 2 sn nnn no ewe ne enna en nen nen ee mene anna nnn a= 0.6 0.5 0.5 
| 
Specimens examined. 
g No. of | 
= | No. of speci- ; 
8 3 mens. 2 
Locality. ee 3 | 
i & | Nature of bot- = ra § 
A a tom. 2 ey) a 
8 N. lat. ° W. long. a FI 3 re) s a 
= By | aI zs 
~~ 2 Rel ‘= 
a A = El A 
Pe i 7 ne 
| OFF MARTHA’S VINEYARD. 
rote elas i u | 1880, 
871 | 40 02 54 70 23 40 | 115 fne. S. M. | Sept. 4 1} \ 0’ | Ale. 
873 40 02 00 70 57 00 100 sft. M. Sept. 13 | 1 1 ile el DY 
874 | 40 00 00 70 57 00 |. 8 M. Sept. 13 1] °-0'| Do, 
Pea 1881. 
| ra. 8. an 
940! 39 54 00 69 51 30 | 134 ; MI EGR. } Aug. 4/2 1 ee i OY 
941} 40 01 00 69 56 00 79 hrd.8., M. | Aug. 4 13 3 | 38 | Do. 
In the manuscript sent to the printer I referred this species to Hlas- 
monotus with considerable hesitation, though it agreed very well with 
the brief diagnosis given by Milne-Edwards (Bull. Mus. Comp. Zool. 
Cambridge, viii, p. 60). The recently published figures of HL. Vaillantii 
(Recueil de figures de Crustacés nouveau ou peu connus, April, 1883), _ 
however, seem to show that my species is generically as well as spe- 
cifically distinct trom Hlasmonotus, being distinguished by the short 
and broad merus of the external maxilliped, the absence of spines, 
teeth, or caring: upon the carapax and abdomen, and by the greater 
breadth of the carapax, if the measurements given by Milne-Edwards, 
are correct.* The species here described is apparently also distin- 
guished generically by the small and non-segmented exopod of the first 
maxilliped, and specially by the rudimentary character of the append- 
ages of the third, fourth, and fifth somites of the abdomen. The number 
