120 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.47. 



Family GRAPSID^. 



Siabfamily GRJi>.FSlN JEl. 



PLANES MARINUS, new species. 

 Plate 3. 



Type-locality. — At sea, west of Lower California, in lat. 23° 49' N.; 

 long. 127° 50' W.; D. D. Raulet, collector. 



Type. — Male, Cat. No. 6065, Mus. Comp. Zool. One male, 1 female, 

 paratypes, Cat. No. 22833, U.S.N.M. 



Dimensions. — Male type, length. 17.6 mm., width 19.3 mm., width of 

 front, 10 mm. 



Carapace convex antero-posteriorly and from side to side; surface 

 covered with j^unctae and fine reticulations; coarser strise cross the 

 anterior half transversely and nearly all the branchial region ob- 

 liquely. Surface of fi'ont covered with short strise and minute gran- 

 ulation; free edge arcuate and faintly bilobed, each lobe appearing in 

 front view slightly bilobed; edge a raised finely granulated rim; post- 

 frontal lobes low. Anteio-lateral margins convex, with one blunt 

 tooth behind the tooth at the angle of the orbit; postero-lateral mar- 

 gins nearly straight, convergent. 



Chelipeds equal, massive; upper and lower margins of arm trans- 

 versely striated, inner expansion irregularly denticulated; outer sur- 

 face of wrist finely striated, tooth at inner angle blunt; surface of 

 palms nearly smooth, shining, punctate, upper surface rounded, cov- 

 ered with finely granulated longitudinal lines which, become oblique 

 proximally. Fingers stout, prehensile edges narrowly gaping, den- 

 tate, a larger tooth at middle of fixed finger. 



Legs short and broad; third foot one and one-half times as long as 

 carapace; merus of third pair three-fifths as broad as long; dactyli 

 short and stumpy, armed with coarse spines. 



Many species of Planes have been described in the past, all of 

 which are referable to variations of P. minutus; ^ but this form ap- 

 pears to be distinct. It has a great resemblance to Pachygrapsus 

 also, and forms a link between the two genera. 



From Planes minutus it differs in its broader carapace, somewhat 

 depressed about the middle instead of uniformly convex; in the 

 postero-lateral margins being nearly straight as in Pachygrapsus, not 

 arcuate as in Planes minutus; in the more extensive striation of the 

 dorsal surface; in the broader basal joint of the antenna; the 

 broader merus-joint of the outer maxilliped, both its inner and outer 

 lobes being more strongly developed; in the feebler dentation of the 

 distal end of the inner expansion of the arm. 



1 Cancer minutus Linnaeus, Syst. Nat., ed. 10, 1768, voL 1, p. 625. 



