ASTACIDiE. 93 



3. Astacus Tkowbridgii Simpson. 



Astacus Trowbr'ulgil Stimpson, Proc. Boston Soc. N". H., T. 6, p. 87 (Soparat. p. 53). 



Figures on PI III. and X. 

 Antennal lamina, fig. 171, a; epistoma, b; spine of the second joint of the exterior antenna, c. 

 PL X. Female type. 



Fem. Obesa, olivacea, chelis obscurioribus ; rostro lato longo, excavato, 

 parce pimctato, medio obsolete canaliculate, lateribus parallelis, mar- 

 ginatis, crassioribus ; acumine triangulari, longo, angusto, acute, fusco- 

 corneo, spinis lateralibus validis; cretis brevioribus, antice spina rejecta; 

 aliaqne ad basin cretoe spina. Antennis corpore brevioribus modicis, ar- 

 ticulis cluobus basalibus dente externo valido ; antennis internis articulo 

 basali dente infero apicali, lamina valida, trigona rostro breviori, modice 

 lata, margine externo crasso, apice spina longa, acuta. Epistomate tri- 

 angulari; pedibus maxillaribus externis intus barbatis. Thorace ovato, 

 antice angustiori, densius punctato, lateribus sublaavibus ; linea profunda, 

 sinuata ; areola lata. Postabdomine thorace latiori, apicem versus de- 

 crescente, laavi, angulis segmentorum externis rotundatis; lamina inter- 

 media quadrangulari, apice, angustiori, utrinque spinis duabus validis, 

 rejectis; parte apicali breviori, fere orbiculari; lamina laterali vix cos- 

 tata, spina media antemarginali, externaque marginali. Pedibus anticis 

 validis, longis, corpore brevioribus ; chela magna, lata, punctata sub- 

 plana, marginibus subacutis, margine interdum recto subtus excavato ; 

 cligitis validis, subsinuatis, chela paulo longioribus, apice spinulosis ; digi- 

 to mobili intus basi exciso ; externo digito basi intus producto ; utroque 

 intus dentato. Carpo lato, truncate, punctato, spina antica interna 

 acuta; subtus spina media antica. Brachio, sublsevi, margine antico 

 et superiori spinoso, spina anteapicali majori ; subtus biseriatim forte 

 spinoso, utrinque ad articulationem spina valida. Ventre inter pedes 

 quartos lsevi ; annulo transverso, cylindrico. 



Long. corp. 4; antenn. 3; ped. antic. 3. 



Habitat : Astoria, Oregon ; " near Astoria it occurs sometimes abun- 

 dantly in brackish water." 



I have seen two female types of Mr. Stimpson's, communicated by 

 the Museum of the Soc. Nat. Hist, in Boston. 



This species differs from A. nigrescens in the broad, rounded lateral an- 

 gles of the abdominal segments. 



4. Astacus Klamathensis Stimpson. 



Astacus Klamatliensis Stimpson, Proc. Bost. Soc. X. EL, T. G, p. 87 (Separat. p. 52). — Bate 

 Spence. Xaturalist in Vancouver's Island and Brit. America, 1866, T. 2, p. 278. 



Figures on PI. III. 

 Antennal lamina, fig. 169, a; epistoma, b; spine of the second joint of the exterior antenna, c. 



Fem. Rostro longo, densius punctato, subplano, medio obsolete 



