NEW CRAYFISHES FROM FLORIDA — HOBBS 417 



punctate dorsolaterally.. lateraliy, and vontrallj-. Tuberculatc doi-so- 

 mesially and mcsially. 



Mci-us with an irregular row of tuberolos (about 30) along dorsal 

 mai^in. Ventrolateral margm with about 18 tubercles. Ventro- 

 inesial row branching from the ventrolateral row mth about 6 tuber- 

 cles. Ventromesial margin with about 21 tubercles; otherwise mostly 

 plane, spai-seiy setose-punctate. 



Ischiopodites of third pereiopods hooked. Caudoventral surface of 

 hook rounded, cephalodorsal surface excavate. Fourth pereiopod 

 with a sliallow groove on the ischiopodite, its raised margin suggest- 

 ing a rudimentarj'- hook; the rounded tubercle distad of the groove 

 very poorly developed. 



First pleopod reaches the coxopodite of third pereiopods, the tip 

 ending in four distinct parts, as follows: The mesial process, a long 

 corneous spine, extending beyond the rest of the appendage distally 

 and bending slightly laterally; the cepliaUc process arising from the 

 anteromesial part of the organ and forming a slender corneous spine; 

 the central projection, an anteroposterior!}^ flattened, triangular process, 

 extending distad beyond the cephalic process, and consisting of two 

 processes, a mesial or centrocephalic process arising from the center 

 of the appendage, and a lateral or centrocephalic process contributed 

 from the lateral surface of the cephalic process; and the caudal 

 process arising from the posterolateral surface and distally bending 

 anteriorly almost at a right angle with, the main shaft. 



Mah {form II). — Differs from the male of the first form in only a 

 few minor points, chiefly in tlie smaller degree of accentuation of the 

 tuberculatc and spiny portions. The complex arrangement of the 

 first pleopod is much simplified and the caudal process is not even 

 present as a vestige. The anterior section of the telson bears two 

 spmes in each posterolateral corner. A small median spine is present 

 on the middle anterior margin of epistome. 



Female allotype. — A reduced heaviness of the chelae is one of the 

 most striking dissimilarities between the two sexes. Annulus vcn- 

 trahs small, movable, wath large irregular tubercles on anterolateral 

 surfaces. The sinus, beginning slightly to the left of the midanterior 

 margin, curves gently to the right of the midventral line, then some- 

 what more sharply to the left, again crossing the midventral line, 

 where it then curves gently once more to the midposterior margin. 

 Just posterior to the amiulus the sternum is modified into a small, 

 trapezoidal, rounded plate, whose surface is broken by about six 

 tubercles; the two occupying tlie posterolateral corners are larger, 

 more nearly spiniform, and are directed mcsially. Surface of sternum, 

 immediately anterior to annulus unbroken, though the median trough 

 is somewhat narrow with overhanging walls. 



