118 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM, 



PYCNOGONIDA. 



Palleue empusa "Wilson, Trans. Conn. Acad. Arts and Sciences, vol. v, p. 9, pi. iii, 

 figs. 2a to 2g, 1878. — Fhoxichilidium maxillare Smith, Inv. of Vineyard Sound, 

 p. 544, 1874 {non Stimpson). 



Found amongst the eel-grass, low water to J fathom. Former 

 localities: Vineyard Sound (TJ. S. F. C, 1871) and JSToank, 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 exuviae were sometimes so abun- 

 dant that they nearly made up the little ridge of debris running along 

 the upper i^art 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, SS""*" ; distance between the 

 tips of the spines surmounting the compound eyes, 31.5°""; length of 

 comiiound eye, 3.5°"". The carapax of the newly expanded animal had 

 a width of G7'""'; length, 45™"; distance between the spines of com- 

 pound eyes, 43"""^; length of comjiound 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, 



