EEPORT ON THE SCHIZOPODA. 193 



author from the Mediterranean. The species of this genus would seem to lead a pelagic 

 existence, most of them being met with at the surface of the sea. 

 The following is a synopsis of the Challenger species : — 



straight. Frontal plate abruptly truncate, . A. tijpicus, Krijyer. 



CaraDace ^¥itll I '^^^ *''^° posterior segments of trunk. Frontal 



posterior e.l^e \ emarginale, ' P''''^'^ triangular, acutely pointed at tip, . A. angustus, G. 0. Sars. 



' ^ " ° I none of the segments of trunk. Frontal margin 



[ only slightly projecting in the middle, . A. pusillm, G. 0. Sar.^. 



posterior edge 



49. Anchialus typicus, Kroyer (PL XXXIV. figs. 4-24). 



Aiichialus typicus, Kroyer, Et Bidrag til Kundskab om Krchsdp'familien Mysidae ; Nat. 



Hist. Tidsskr., 2""" Esekke, Bd. i. p. 53, Tab. ii. figs. 7, a-l. 

 Mijsis moehii, Dohrn, Untersuchuugen iiber Ban und Entwickelung der Arthropoden, II. ; 



Zeifcschr. f. wiss. Zool., Bd. xxL, 1871, p. 359, Tab. xxvii., xxviii. figs. 11-22. 

 Anchialus truncatus, G. 0. Sars, Preliminary Notices on the Challenger Schizopoda, No. 47. 



Specific Characters. — Form of body short and thickset. Carapace large, covering 

 whole of trunk, posterior margin straight. Frontal plate abruptly truncate at tip. Last 

 caudal segment a trifle longer than preceding. Eyes thick, claviform, cornea slightly 

 expanded, with light yellowish pigment. Antennular peduncle short and stout, with 

 middle joint cup-shaped. Antennal scale exceedingly minute, rhomboidal, denticle of 

 outer corner obsolete. Gnathopoda very strong, with carpal joint in male projecting at 

 the inner edge as a pointed process. Legs comparatively short, with terminal part very 

 .small, and divided into four to five articulations ; first pair in male having terminal part 

 dilated in the middle and armed with peculiar slender spines. Caudal limbs in female 

 distinctly developed on first segment only, those of male, strong, with basal lobe of inner 

 branch very broad, lamellar ; outer branch of fourth pair but slightly produced. Telson 

 very large, oblong linear, apical incision occupying one-seventh of the length. Uropoda 

 with inner plate somewhat larger than outer, and having the auditory apparatus but 

 slightly developed ; outer plate with exterior edge armed with a row of small denticles. 

 Marginal setse of both plates very small. Length, 9 mm. 



Remarhs. — I recorded this form in my Preliminary Notices as a new species under 

 the name oi Anchialus truncatus, but now believe it to he identical with the Anchialus 

 typicus of Kroyer. The figures given by that author do not, it is true, correspond 

 exactly with the form examined by myself ; but I think this may be merely accounted 

 for by the imperfect drawings given by Kroyer. His description would seem, for the 

 most part, to accord with the present species. I cannot but believe that the form 

 recorded by Dohrn as Mysis moehii belongs to this .species. As regards the Mediterranean 

 species, Anchialus agilis, G. 0. Sars, the similarit}- to the present form, both in the 



(ZOOL. CHALL. EXP. PART XXXVII. — 1885.) Oo 25 



