262 ZOOLOGY. 



upon the extend of tlie first segment, the third being considerably developed upon its upper 

 region, which is prominently convex. The remaining portion of the tail is very much reduced, 

 tapering posteriorly, bent downwards and forwards under the body. The lateral and free 

 expansions of the anterior three caudal segments are rounded oif ; that of the second segment 

 is the largest, subcircular in shape, external, and covering partly the expansions of the first 

 and the third segments. In the fourth and fifth segments that expansion is subtriangular, 

 posteriorly acute. The sixth ring has no such lamellar expansions, but is provided upon its 

 posterior and inferior angle with a slight ridge, at the inner margin of which a row of sette is 

 observed similar to that which exists upon the external margin of the lamelhB of the other 

 segments. The central caudal appendage, subconical in shape, elongated and tapering, is con- 

 vex above, concave beneath, and terminated by three pairs of spines; a very minute external 

 pair, and two median, the uj^per one very slender, and two thirds tlie length of the lower pair, 

 which is the most conspicuous. Along the upper and convex surface there are three pairs of 

 rather short, stoutish, though small spines. On each side of this central appendage, and 

 inserted in a concavity of the lateral and posterior edge of the sixth segment, with one spiny pro- 

 cessus above and below, is another appendage composed of a sliort basal piece, upon which are 

 inserted two moveable very thin lanceolated lamellas, provided upon their edges with well devel- 

 oped seta3 disposed upon one close series. The inner lamella is made of a solitary piece; the 

 external one is composed of two pieces, the undulated and transversal articulation of which 

 may be seen across the posterior third of said lamella, exteriorly marked by two small spines 

 belonging to the largest piece. 



The caudal or oviferic legs, five in number (one jiair for each anterior five caudal segments), 

 are of moderate development, the second and third pair being the largest. The posterior four 

 pairs are similarly constructed. They consist of a flattened article, terminated by two narrow, 

 elongated, thin blades, margined with setaj. The anterior pair is distinguished from the others 

 in the structure of the terminal pieces, the inner of which is short and rather broad, and de- 

 prived of setaj upon its edge, whilst the outer one is similar to those of the other legs, being, 

 however, considerably smaller. 



The surface of the carapax is almost entirely smooth ; a minute, prickly granulation becomes 

 visible under a magnifying glass and to the touch also. This granulation is more apparent 

 upon the locomotory and other appendages than elsewhere. The upper margin of the large claw 

 is provided with an elongated tuft of setaj extending from the anterior portion of the hand 

 (so called) along the convexity of the finger to near its apex. An elongated cushion of short 

 seta3 may also be observed along the convexity of the finger to near its apex. An elongated 

 cushion of short setaj may also be observed along the inner surface of the tliird, fourth, and the 

 base of the fifth article of the jaw-legs. Scattered bristles or setaj exist along the inner surface 

 of most of the articles constituting the legs, and principally upon the mandibles. 



The ground-color is yellowish ; the sides of the cephalothorax and tail are variegated with 

 irregularly meandric, fuliginous red maculaj. The appendages are annulated with purplish 

 red. The third caudal ring is purplish upon its convexity, exhibiting two parallel light vitt^e 

 along the upper surface of the anterior three rings, uniting at an acute angle upon the poste- 

 rior portion of the third ring. The caudal legs are spotted with fuliginous red. 



The specimens were caught in Caldera bay. 



