Pacifastacus leniusculus trowbridgii ( Stimpson, 1857 )

Pacifastacus leniusculus trowbridgii ( Stimpson, 1857) View in CoL

( Figs. 5 View Figure 5 , 6 View Figure 6 ; Tab.2)

Description of the syntypes. Eye large (diameter 3.4 mm), cephalothorax ( Fig. 5A View Figure 5 ) subcylindrical, thoracic section dorsoventrally depressed, feebly tuberculated dorsally and dorsolaterally, cephalic section laterally with moderate tubercles, areola 2.5 times as long as wide, constituting 33.9 % of TCL (42.4 % of POCL). Rostrum ( Fig. 5B View Figure 5 ) non-serrate, margins converging from base to base of acumen, broad at base and lacking median carina, with moderately elevated, slightly thickened margins and tubercles, latter weakly converging to base of acumen, with single right side (left 1) marginal tubercles, length of acumen seldom equal to width of rostrum at level of marginal spines, margins not constricted at base of acumen, more strongly converging and moderately concave to dorsally directed apex, tip of which reaching slightly cephalic to distal margin of antennal scale and not reaching distal margin of penultimate podomere of antennular peduncle, acumen comprising 43.9 % of rostrum length, latter comprising 21.4 % of TCL, floor (dorsal surface) of rostrum with small marks, suborbital ridge not visible in dorsal aspect, postorbital ridge rounded or tuberculiform cephalically and with or without low tuberculiform prominences at posterior bases ( Fig. 5B, C View Figure 5 ).

Carapace ( Fig. 5A, B View Figure 5 ) 1.1 times wider than greatest width of abdomen, abdominal pleura with margins subangular ( Fig. 5E View Figure 5 ), terminal slightly rounded, surface punctate, terga slightly punctuate, articular surfaces glabrous. Incisor region of mandible dentate-crenate ( Fig. 6A View Figure 6 ). Proximal podomere of uropod ( Fig. 5F View Figure 5 ) with small caudolateral spine on lobe, larger spine on mesial lobe, mesial ramus of uropod with moderate caudolateral spine, left lateral ramus of uropod with caudolateral spine; telson with two (1 in left) spines at caudolateral corner of cephalic section, lacking transverse suture.

Antennal scale ( Fig. 6B View Figure 6 ) 2.1 times as long as broad, widest at midlength, lateral margin thickened and terminating in long distal spine. Third maxilliped with tip of endopodite extending nearly to distal margin of penultimate podomere of antennal scale peduncle, tip of basal podomere of exopodite extending beyond midlength of merus of endopodite; mesial of merus ( Fig. 6C View Figure 6 ) with row of spines, spine of distal end largest; longitudinal ridge of ventrolateral margin of ischium with row of punctuations; ventrolateral half of ischium punctate, distolateral corner with small tubercle, ventromesial half with long, obscuring bristles on mesial margin, latter with denticles, distomesial corner having larger spine.

Total length of cheliped 107.6 % of TCL, mesial margin of palm ( Fig. 5D View Figure 5 ) 0.9 times wider than long, 1.5 times wider than deep; articular ridge strong, proximal margin well defined, ventral surface punctuated, lacking tubercles, distolateral part with weak depression and moderately punctate, not costate, articular ridge strong. Fingers of chela not gaping, dorsal surface and ventral surface with punctuation, not costate, lacking longitudinal ridge, opposable surface of fixed finger with row of 13 (9 left) moderate tubercles. Fixed finger not costate, dorsal and ventral surfaces punctate, lacking longitudinal ridge, opposable surface with row of conical and equal size tubercles. Dactyl of chelae 1.4 times as long as mesial margin of palm, comprising 54.1 % of total chela length; dorsal surface of dactyl lacking longitudinal ridge, mesial surface with seta originating from marks, ventral surface punctate, lacking ridge, opposable surface with single row of equal size tubercles. Carpus of cheliped 1.1 times as long as wide, 0.8 times length of mesial margin of palm, dorsal surface with long, slightly oblique sulcus, surface lateral and mesial to sulcus punctate, mesial surface of carpus with large, strong spines, ventral surface with conical distal mounds, distomesial one tipped with spine. Merus of cheliped 1.8 times longer than greatest depth, length 39.4 % of TCL; dorsal surface with single row of large, small tubercles; ventrolateral ridge with large, stout tubercles, ventromesial ridge with stout, acute tubercles.

Ischia of pereiopods lacking hook ( Fig. 6D View Figure 6 ). Gonopods (first pleopods) ( Fig. 6E View Figure 6 ) of male

A B C

symmetrical in caudal aspect, well developed, distal portion ( Fig. 6F, G View Figure 6 ) rolled and contracted to form narrow tube, lacking lobes apically. Length of tubular part 3 times longer than gonopod length; distal portion converging to tip, lacking corneous distal portion. Second pleopod ( Fig. 6H, I View Figure 6 ) single stout shaft with deep suture near midlength, exopodite originating from suture not reaching distal margin of endopodite, palps originating on distal portion of shaft. Annulus ventralis of female lacking ( Fig. 6J View Figure 6 ).

Deposition and type locality. The syntypes of P. leniusculus trowbridgii are 2 males and 2 females ( USNM 2080 About USNM ) collected by Lt. Trowbridge from Columbia River , above Astoria ( Stimpson, 1857) .