ASTACID.E. 93 



3. Astacus Trowbeidgii Stimpson. 



Aslacus Troiobridgii Stiuipson, Proc. Boston Soc. X. H., T. 6, p. 87 (Separat. p. 53). 

 Figure? on PI III. and X. 



Antennal lamina, fig. 171, a; epistoma, 6; spine of the second joint of the exterior antenna, c. 

 PI. X. Female type. 



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

 parce punctate, medio obsolete canaliculato, lateribus parallelis, mar- 

 ginatis, crassioribus ; aeumine triangulari, longo, angusto, acuto, fusco- 

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

 aliaque ad basin cretae spina. Antennis corpore brevioribus modicis, ar- 

 ticulis duobus basalibus dente externo valido ; antennis intends 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 sublaevibus; linea profunda, 

 sinuata : areola lata. Postabdomine thorace latiori, apieem versus de- 

 crescente, hvvi. 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 antieis 

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

 plana, marginibus subacutis, margine interdum recto subtus excavato; 

 digitis 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, sublaevi, margine antico 

 et superiori spinoso, spina anteapicali majori ; subtus biseriatim forte 

 spinoso, utrinque ad articulationem spina valida. Ventre inter pedes 

 quartos hvvi ; 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. nigrescem in the broad, rounded lateral an- 

 gles of the abdominal segments. 



4. Astacus Klaatatiiexsis Stimpson. 



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

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

 Figures on PI. III. 

 Antennal lamina, fig. 1C3, a; epistoma. h ; spine of the second joint of the exterior antenna, c. 



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



