MR. E. J. MIERS ON THE OXYSTOMATOUS CRUSTACEA. 243 



A Revision of the Species of the Genus Matuta. 

 Matuta, Eabricius. 

 In the species of this genus the carapace is usually slightly broader than long, broadest 

 and with a strong, conical, acute, lateral spine at the junction of the anterolateral and 

 posterolateral margins. The front is about equal to the orbit in width, slightly con- 

 cave above, with a projecting median lobe, which in some species is notched, in others 

 entire. The anterolateral margins are rather convex, with about six small tubercles 

 behind the external orbital angle, and following them usually three granulated, larger 

 tubercles. The posterolateral margin is straight, with a tubercle, that is sometimes 

 obsolete, placed at some distance behind the lateral line. In the central region of the 

 carapace are six tubercles, of which some, or all, may be obsolete ; three of these are 

 placed in a median transverse series, one anterior on each side of the gastric, and one 

 posterior in the centre of the cardiac region. The anterior legs are robust, and may be 

 closely applied to the body ; the arm is smooth, the wrist slightly taberculated upon its 

 external surface ; the upper margin of the hand has three prominent, acute lobes or 

 spines ; on the upper part of the external surface are three transverse ridges, or two 

 parallel series of three tubercles ; below these, on the outer surface, a ridge, or series of 

 tubercles and spines, the direction and form of which varies in the different species of 

 the genus ; on the inner surface two small striated areas. The external surface of the 

 mobile finger in the male is usually transversely striated or beaded. The four following, 

 pairs of legs have the two terminal joints more or less expanded and compressed; the 

 expansion of the terminal joint is greatest in the first and fourth, and least in the third 

 pair of legs; and this joint is acute at the extremity in the first three, and rounded in 

 the last pair of legs. 



(A) Hand of male with an interrupted ridge or series of spines and tubercles crossing its outer surface 

 obliquely, and continued along the outer surface of the lower {immobile) finger. Upper {mobile) finger 

 with a strongly beaded ridge extending throughout its whole length. 



{a) Carapace covered with numerous dark-red spots. 



1. Matuta victrix. (Plate XXXIX. figs. 1-3.) ^vW« ' 



Cancer victor, Fabr. Spec. Ins. ii. Append, p. 502 (1781) ; Ent. Syst. ii. p. 449 (1798)? 



Matuta victor, Fabr. Ent. Syst. Suppl. p. 369 (1798) ; ? M.-Edw. Hist. Nat. Crust, ii. p. 115, pi. xx. 



figs. 3-6 (1837) ; Regne Animal de Cuvier, Atlas, Crustaces, pi. vii. fig. 1. 

 Matuta peronii, Leach, Zool. Miscell. iii. p. 13, pi. 127. figs. 1, 2 (1817) ? . 

 Matuta lesueurii, Leach, Zool. Miscell. iii. p. 14 (1817) d ■ 



Carapace finely but distinctly granulated ; two anterior tubercles of the carapace obso- 

 lete, the remainder, as well as that upon each posterolateral margin, faintly marked ; 

 lateral marginal spine long, and directed slightly forward. Eront slightly emar- 

 ginate, with the lobes rounded. Hand not granulous upon its external surface, the 

 ■ tubercles on the upper half sharply defined ; a small tubercle, followed by a very 

 strong, conical spine at the base of the oblique ridge, which is interrupted at base, 



SECOND SERIES. — ZOOLOGY, VOL. I. 2 K 



