118 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 
PYCNOGONIDA. 
Pallene empusa Wilson, Trans. Conn. Acad. Arts and Sciences, vol. v, p. 9, pl. iii, 
figs. 2a to 2g, 1878.—Phoxichilidium maxillare Smith, Inv. of Vineyard: Sound, 
p. 544, 1874 (non Stimpson). 
Found amongst the eel-grass, low water to 4 fathom. Former 
localities: Vineyard Sound (U. 8S. F. C., 1871) and Noank, Conn. (U. 
S. F. C., 1874). 
MEROSTOMATA. 
Limulus Polyphemus Latreille. Smith, Inv. V. S., p. 580, 1874. 
Very common along the entire inner shore of the cape, in the vicinity 
of Provincetown. The living specimens were usually encountered partly 
buried in the sand, near low-water mark. They sometimes attain a very 
large size in this region, but the majority of the specimens seen were 
from small to medium size and females. All the larger specimens col- 
lected were males. The cast skins or exuvize were sometimes so abun- 
dant that they nearly made up the little ridge of débris running along 
the upper part of the beaches. 
Two specimens, both females, were obtained in the act of molting; 
one was living, the other dead. In the case of the latter the operation 
of throwing off the old skin had advanced considerably, allowing us to 
measure accurately the increase in the size of the carapax for the past 
year. Of the exuvia, the greatest width of the carapax was 57™™; 
length of carapax along the median line, 35™™; distance between the 
tips of the spines surmounting the compound eyes, 31.5"™; length of 
compound eye, 3.5™". The carapax of the newly expanded animal had 
a width of 67™™; length, 45™"; distance between the spines of com- 
pound eyes, 45™"; length of compound eye, 5™". The living specimen 
had only broken slightly through the outer skin, so that but one meas- 
urement could be made without destroying it. The width of the old 
carapax was 124™™", of the new 141™™; but as the latter had suffered 
contraction in alcohol, it must have been larger originally. 
DECAPODA. 
Gelasimus pugnax Smith, Trans. Conn. Acad., vol. ii, p. 131, 1870; ibid., vol. v, p. 
33, 1879; Inv. V. S., p. 545, 1874. 
Very abundant on the salt marshes and upper part of the beaches, 
between the town and Wood End Light. Also found at the same place 
by Prof. S. I. Smith and Mr. O. Harger, in 1872. 
Gelasimus pugilator Latreille. Smith, Trans. Conn. Acad., vol. ii, p. 136, 1870; ibid., 
vol. v, p. 33, 1879; Inv. V. S.,.p: 545, 1874. 
A few specimens only of this species have been noticed from Province- 
town; they were found on the beach near the dike in 1872, by Smith 
and Harger. 
