272 [Septembeb, 



Paguristes hirtijs. Rostrum brevissimum. Carapax plerumque hirtus. 

 Oculi graciles margine carapacis antico non breviores, basi vel aciculo antenna- 

 rum extemarum multo longiores, basi internarum breviores, squama basali valde 

 elongata, angusta, margine externo arcuato et tenuiter bene denticulato. 

 Flagellum antennarum extemarum infra elongate ciliatum. Pedes 2di 3tii hirti 

 crassiusculi. 



Long. 2". Hah. in mari Sinensi. 



GENUS CENOBITA. 



Cenobita carnescens. Regio carapacis antica plana, scabricula, lateribus 

 quoque plana. Oculi fronte longiores, plus duplo longiores quam altitudo, valde 

 compressi, squama basali triangulata, acuta. Pedes antici inaequi,sinistromajore, 

 superficiem granuloso, carpo paulo breviore quam manus, brachio apicem oblique 

 plano-truncato. Pedes quatuor sequentes fere nudi, parce pubescentes, articulo 

 ultimo scabriculo. 



Long. U li". Hah. in archipelago " Paumotu." 



Cenobita brunnea. Regio carapacis convexa, nuda. Oculi fronte paulo 

 breviores. Pedes antici validi, paulo inaequi, manu carpoque hirsutis, manu 

 spinulis minutis sparsis scabricula, brachio apicem rotundato. Pedes 4 sequentes 

 hirsuti, articulo ultimo subterete, longiore quam penultimus. 



Long. 3". Hah. ad insulam " Upolu" Samoensem. Abdomen nuce myristico 

 saepe tectum. 



The Committee to which was referred Dr. J. C. Fisher's description 

 of a new species of Cicada, with Mr. Cassin's Notes on the same and 

 on C. septendecim, reported in favor of publication in the Proceedings. 



On a 7ieto species of Cicada. 

 By J. C. Fisher, M. D. 



In the course of the observations made by the Committee of this Academy, to 

 which vi^as assigned the duty of investigating the habits and history of the seven- 

 teen year Locust, Cicada septendecim, which appeared during the present year 

 (1851) in the neighborhood of Philadelphia, the attention of its members was di- 

 rected by Mr. John Cassin to the fact, that two species had been confounded, and 

 that the insect regarded as the smaller variety was in fact a distinct species, a 

 conclusion at which he had arrived during their previous appearance in 1834. It 

 is much smaller, is blacker in color, especially on the lower surface of the abdo- 

 men, where also the segments are bordered more narrowly with yellow, and has 

 a note entirely different from that of the larger Cicada septendecim, Linn. Syst. 

 Nat. 1. pt. ii.p. 708, (1767.) 



The two species did not associate together, but were found mostly on separate 

 trees, the smaller being the less abundant. 



I propose on these grounds to characterize the smaller species as follows : 



Cicada Cassinii, nobis. J total length of body 9-lOths of an inch, of the wings 

 1 2-lOths inches ; ^ frequently smaller. 



Colors and general appearance much like those of Cicada septendecim, Linn., 



