astacid^:. 95 



fere parallelis. Pedes 5 li branchias parvas gerentes. Hab. flumine Co- 

 lumbia?," Oregoniae. Long. 4". — Dana. 



In the description Mr. Dana says, u arm with anterior margin den- 

 ticulate, and a longer tooth at apex, on outer margin, short distance 

 from apex, unispinous." 



" May be recognized by its well-developed thoracic spines, and light 

 color. Has a general resemblance to A. Troivhridgii ; differs from that 

 species in having more prominent thoracic spines ; the rostrum is some- 

 what shorter and broader, the dorsal area broader." — Stimpson. 



Habitat: Columbia River; Puget Sound. 



I have not seen this species, which seems to be very similar to A. 

 nigrescens, except in the non-denticulated margin of the rostrum. The 

 description and the figure given by Mr. Dana are not sufficient. 



6. Astacus Oeeganus Randall 



Astacus Oreganus Randall, Journ. Acad. N. S. Philad., T. 8, PI. I., p. 138, t. 7. — Erichson, 

 Wiegm. Arch., T. 12, p. 375. — Girard, Proc. Acad. N. S. Philad., T. 6, p. 87. — Stimpson, 

 Proc. Boston Soc. N. H., T. 6, p. 87 (Separat. p. 55). 



" Body fuscous, granulated, carpus with a sharp spine at the interior 

 angle ; arm produced into a spine on each side anteriorly ; thorax be- 

 hind the front with five spines, placed three before and one on each 

 side behind the lateral ones ; a large reddish spot on each side posteri- 

 orly ; front little reflected on the sides, terminating in a very long, slen- 

 der spine, and having a short, marginal spine on each side. Long. 4". 

 Columbia River. 



" Testa granulata, bimaculata, fronte valde producta." — Randall. 



Erichson, in his translation of this description, makes a mistake, " das 

 Magenfeld an jeder Seite mit fuenf Dornen, naemlich drei vor und zwei 

 hinter den Seitendornen " ; Randall by no means says that there are five 

 spines on each side. 



" Dr. Randall's single specimen of this species was unfortunately lost 

 by the artist employed in delineating it. No other example has been 

 since found, although its locality has been since repeatedly searched. 

 If the figure in the eighth volume, etc., is correct, this is a very remark- 

 able species, differing from all others known, in possessing a median 

 thoracic spine as well as in the length of the terminal rostral tooth, and 

 above all in the singular lateral appendages of the abdominal seg- 

 ments." — Stimpson. 



The figure published by Randall is without doubt very incorrect, giv- 

 ing one segment too much in the postabdomen, and a little claw at the 

 tips of the fourth pair of legs. The curious lateral appendages to the 

 segments of the postabdomen are probably its lateral angles, acute as 

 in A. nigrescem, or the artificially protruded abdominal legs. Mr. Ran- 



