214 SMITHSONIAN MISCELLANEOUS COLLECTIONS 



pax, 0.44 ; breadth of front, 0.22 ; length of eye, 0.23 ; of cheliped, 

 0.7 inch. 



Found on rocky shores at half-tide, in Kagosima Bay, Japan. 



Genus SPIROPAGURUS Stimpson 



Carapax depressed, anteriorly sufficiently indurated, but pos- 

 teriorly membranaceous, the cardiaco-branchial sutures being, how- 

 ever, strengthened by linear corneous strips. Eyes short, with the 

 cornea dilated. Antennae large ; acicle slender from its base. Left 

 virgula or genital organ of the left coxa of the fifth pair of feet in 

 the male, persistently exserted to a considerable length, slender, com- 

 pressed, spiral, and membranaceous, with the superior margin 

 strengthened by a corneous strip. Last segment of the abdomen 

 bifid at the extremity ; margins of the forks serrated. 



In most characters besides those mentioned in tiie above descrip- 

 tion this genus agrees with Eupagiinis. the maxillipeds being remote 

 at base, with small cox?e ; the chelipeds more or less unequal, with 

 the right one largest, and the fourth pair of feet scarcely subcheli- 

 form, sometimes nearl\- simple, with compressed dactylus. Its most 

 remarkable characteristic is seen in the exserted left genital organ_ 

 of the male, forming a "spire" or coil of one or two turns. Some- 

 thing of this kind is seen in some Cciiobitcr, in which, however, the 

 coxae are i)roduced on both sides, although to a different length, and 

 indurated. 



The genus was founded u])on the Pogunis spiriger of De Haan. 

 which was, until recently, the only known species. The Ley den 

 carcinologist mentions the "spire." but has not, apparently, recog- 

 nized its identity with the male genital organ. 



Only one other species is known, S. dispar Stm., which inhabits 

 the Caribbean Sea. 



334. SPIROPAGURUS SPIRIGER (De Haan) Stimpson 



Pagiirus spiriger De Haan, Fauna Japonica, Crust., 206, pi. xux, fig. 2. 

 Spiropagtirus spiriger Stimpson, Proc. Acad. Nat. Sci. Phila.. x, p. 248 

 [86], 1858. 



The following specific characters may be mentioned in addition to 

 those given by De Haan : The median and lateral points of the front 

 are obtuse. Posterior part of the carapax longer than the anterior 

 part and lineolated or squamose in appearance ; squamae minutely 

 crenulated. Ophthalmic scales large, broad, and obtuse. Flagella 

 of the antennae almost entireh- naked, and overreaching: the ambu- 



