406 G. 0. SAKS, [t. XIII 



size, with the outer edge smooth and produced at the end to a dentiform pro- 

 jection, tip more or less obliquely truncated, with the inner corner projecting 

 beyond the spine of the outer, and having a small apical segment cut off by 

 a transverse suture. Anterior and posterior lips, as also the mandibles (PI. Ill, 

 figs 5, 6) of the usual structure. First pair of inaxillae (PI. Ill, fig. 7) with 

 the exognate quite rudimentary, forming only a slight lamellar ridge finely 

 ciliated on the edge, but without any trace of setae. Second pair of inaxillse 

 (PI. Ill, fig. 8, PI. IV, V, VI, fig. 5) with the terminal joint of the palp oval 

 in form, and edged exteriorly by strong ciliated setae, exognath comparati- 

 vely small and triangular in form, its outer edge but slightly curved, mar- 

 ginal setae rather short and uniform in size. Maxillipeds (PI. Ill, fig. 9) with 

 the basal lobe rather large, outer masticatory lobe well -developed, though 

 scarcely as large as the basal one. Gnathopoda (PI. Ill, fig. 10) comparati- 

 vely less robust than in Paramysis, otherwise of much the same structure. 

 Pereiopoda (PL III, fig. 11, PI. IV, V, VI, fig. 6) likewise rather similar 

 to those in the said genus, though comparatively less robust, with the ischial 

 and meral joints less expanded, tarsal part quadriarticulate, with the 1 st 

 articulation very short and obliquely truncated at the tip, dactylar joint 

 small, with the terminal claw well defined from the joint and very slender 

 (see PI. Ill, fig. 12, PI. V, VI, fig. 7). Outer sexual appendages of male 

 as also the pleopoda (PI. IV, figs 11, 12, PI. V, VI, figs 12, 13) of a simi- 

 lar structure as in Paramysis. Telson (PI. Ill, fig. 14, PI. IV, fig. 7, Pl.-V, 

 VI, fig. 8) of moderate size, oblong quadrangular in form, and somewhat 

 tapering clistally, lateral edges densely spinulose, apical sinus very shallow 

 or quite obsolete, its edge bordered by a dense series of spiniform pro- 

 jections, arranged in a regular comb-like manner. Uropoda of the usual 

 structure. 



Remarks. — This genus was characterised by Mr. Czerniavsky as 

 being intermediate between Mysis s. str. and Paramysis. It comes, however, 

 in fact still nearer to the genus Austromysis of the same author, the type 

 of which is M. Hellen G. 0. Sars. The latter genus was not adopted by the 

 Rev. Mr. Norman , who referred its species to his genus Schistomysis, founded 

 upon some of the species referred by Mr. Czerniavsky to his genus Syn- 

 mysis. I fully agree with Mr. Norman, that the 3 species M. Spiritus, M. 

 ornata and M. assimilés cannot properly be placed in the same genus with 

 M. flexuosa and M. neglecta, which, according to that author, belong to the 

 genus Macromysis of White. On the other hand, I think that the genus 

 Austromysis of Czerniavsky may be retained in the sense of that author, 

 including probably also the British species M. ParJceri. From the last named 

 genus the present one is chiefly distinguished by the less obliquely truncated 



Bulletin N. S. IV (XXXVI) p. 58. 



