700 T. R. R. STEBBING. 



Gen. Calathura, Norman and Stebbing. 



Calathura, 1886^ Norman and Stebbing, Trans. Zool. Soc. London, Vol. xii. Pt. 4, p. 122; 

 1893, Stebbing, History of Crustacea, p. 332; 1897, Sars, Crustacea of Norway, Vol. II. Pt. 3, 

 p. 44; 1901, H. Richardson, Proc. U.S. Mus. Vol. xxiii. p. 509; 1901, Axel Ohlin, Bihang till 

 K. Svenska Vet.-Akad. Handlingar, Vol. xxvi. Pt. 4, p. 17. 



The genus was instituted to receive Anthura h-achiata, Stimpson, of which Paranthtira 

 norvegica, Sars, and Paranthura urctica. Heller, were considered to be synonyms. Sars in 

 1897 maintains the distinctness of his C. norvegica, which Ohlin in 1901 refuses to admit. 

 The C. affinis of Bonnier belongs, as I have earlier argued, rather to Paranthura or 

 Leptanthura. In 1901 Miss Richardson added a new species, C. crenulata, from the Bahamas 

 and Yucatan. If we admit the presence of eyes in C. hraclnata, as affirmed by Harger 

 and Heller and Sars, but denied by Ohlin, the species of the genus may be distinguished 

 as follows: — 



(Eyes wanting. 1. G. norvegica, Sars. 



JEyes present. — 2. 



(Eyes feebly developed, with pigment white. 2. C. hrachiata (Stimpson). 



(Eyes well developed, with pigment black. — 3. 



(Head only half as long as first peraeon-segment. 3. C. cremdata, Richardson. 



JHead much longer than half the first peraeon-segment. 4. C. horradailei, n. sp. 



It is not altogether improbable that the second species which Haswell referred to his 

 genus Haliophasma, namely H. maculatum, may when more fully described have to be 

 transferred from that genus to Calathura. 



1. Calathura horradailei, n. sp. PI. XLIX A. 



Head with distinct rostral point, the lateral angles strongly produced. Segments of 

 peraeon stout, apparently not carinate at the sides, the first as usual closely attached to 

 the head, and the second distally narrowed, the seventh segment much the shortest. 

 Segments of the pleon all distinct. The long narrowly oval telson has the apex fringed with 

 setae nearly as long as itself, with scarcely perceptible crenulation. There is no appearance 

 in it of ' statocysts ' such as those described in Anthura gracilis by A. Thienemann {Zool. 

 Ameiger, Vol. xxvi. May 8, 1903). 



The eyes are black, subtriangular, with the apex upward, situated near the antero- 

 lateral angles of the head, which are rounded, not acute as they appear in a dorsal view. 



The first antennae have the first joint of the peduncle longer than the other two 

 combined, and a tlagellum of twenty-one joints, the first seven stout, the rest filiform. The 

 second antennae have a long second joint between two shorter joints, the fourth much longer 

 than the third, and the fifth as long as the second. The flagellum, fringed with short setae, 

 is composed of twenty-two joints. 



The horny-pointed mandibles have the third joint of the palps the longest and probably 

 armed with spines, though they were not actually seen. The second maxillae are evidently 

 present, very slender, armed with long setae, and joining with the lower lip and maxillipeds 

 to form a tube. In the maxillipeds it is difficult to determine whether that which Sars 

 claims as the very short first joint of the palp may not be the base of the large joint 



