130 Memoirs of the Indian Museum. [Vol. IV, 



The form of the articulation of the ischium and merus of the raptorial claw 

 leads me to believe that the affinities of this genus are with Squilla, Pseudosquilla, 

 and Lysiosquilla rather than with Odontodactylus and Gonodactylus. 



Of the three known species one inhabits the Atlantic and two the Indo-Paciflc. 

 The Atlantic form, C. bradyi, is very closely allied to C. trachura and the two may, 

 in fact, belong to the same species ; C. bradyi is only known from a single example 

 described in 1869. C. multituberculata, though very different in general appearance, 

 must certainly be accommodated in this genus. 



Key to the species of Coronida. 

 I. Mandibular palp present ; external margin of raptorial dactylus with a 

 single blunt lobe at base ; dorsal surface of last abdominal somite and 

 telson covered with spinules ; form broad, greatest width of abdomen 

 more than one-fifth of total length. 



A. Spinules simple, covering last abdominal somite and telson only . . [bradyi.'] 



B. Spinules stellate, covering last abdominal somite and telson and, in 



addition, posterior half of fifth somite . . . . . . trachura, p. 130. 



II. Mandibular palp absent ; external margin of raptorial dactylus with three 

 teeth ; fifth abdominal somite smooth and unarmed ; sixth with eight 

 dorsal ridges ; telson with two median dorsal carinae and numerous 

 large tubercles on either side ; form narrow, greatest breadth of abdo- 

 men much less than one-fifth of total length .. .. .. multituberculata, p. 132. 



1, Coronida trachura (v. Martens). 



1881. Gonodactylus trachurus, v. Martens, Sitz.-ber. Ges. naturf. Freunde, Berlin, p. 93. 

 Gonodactylus trachurus, Miers, Proc. Zool. Soc, p. 16, pi. i, figs. 3, 3a. 

 Coronida trachura, Brooks, Voy. H.M.S. ' Challenger,' XVI, Stomatop., pp. 7 and 97-80. 

 Odontodactylus trachurus, Bigelow, Proc. U.S. Nat. Mus., XVII, p. 496. 

 Coronida trachura, Nobili, Ann. Sei. Nat. Zool. (9), IV, p. 334. 



The carapace is smooth without trace of carinae and is widest posteriorly, its great- 

 est breadth being about equal to its median length including the rostrum. The gastric 

 grooves are well marked, and on either side of them faint traces of the transverse 

 cervical groove may be observed. The antero-lateral angles are angular but not pro- 

 duced as spines, the postero-lateral are very broadly rounded. The rostrum is sub- 

 rectangular, much wider than long ; its lateral margins are parallel, the antero-lateral 

 angles almost rectangular, and the apex is formed by a blunt obtuse or subrectangular 

 prominence. 



The eyes are about one-third the length of the carapace, excluding the rostrum. 

 The cornea is prominently bilobed, set transversely on the stalk, and in breadth is 

 rather less than the total length of the whole organ. The ophthalmic somite termi- 

 nates in a small acute apex. The antennular peduncle is a little shorter than the 

 carapace excluding the rostrum. The mandibular palp is three-segmented. 



The outer inferior margin of the merus of the raptorial claw is broadly rounded 

 distally ; the carpus has a dorsal carina which is cut into one or two sharp teeth near its 

 distal end. The propodus bears three movable spines at the base of the margin opposed 



