THE SCHIZOPODA. 



I. The Order MYSIDACEA. 

 A. Suborder LOPHOGASTRIDA. 

 CHALARASPIS Willemoes-Sdhm (1S75). 



Descripiion. — Inleguinciit soft. Carapace thin, Huljmembranaceous, with- 

 out processes, anteriorly produced as a \-ery broad but somewhat short frontal 

 plate (Plate 1, fig. la), and with the postero-lateral rounded wings reaching 

 to the end of the thorax or a little more backwards; the cervical groove very 

 strong. 



Eyes small, light reddish. Antennular peduncles (figs, la-lb) short and 

 extremely thick; inner flagellum thin, aliout as long as the peduncle. — Antennal 

 scjuanui not jointed, with the outer margin serrate beyond the midtlle (fig. Ic). — 

 Maxillulae (fig. le) without palp and witliout setae or spines on i\w inner lobe. — 

 Maxillae (fig. If) somewhat reduced; the lobe from second (1'-) and third (P) 

 joint distally rounded, undivided; the palp (p) very short, unjointed, and scarcely 

 marked off; the exopod strongly developed, very broad. — Maxillipeds (fig. Ig) 

 with the exopod about as long as the endopod, which distally is a little broader 

 than in Lophogaster. 



Gnathopods slightly shorter tlian tiie following pair of legs, shaped as in 

 Lophogaster, with the seventh joint somewhat thick, a. little cur\'ed, distally 

 rounded, and strongly setose. — Legs somewhat slender, and the last pair (fig. li) 

 considerably thinner than the first (fig. Ih) or second pair; claw long or very 

 long, thin; exopod well developed in all pairs (the ovigerous female is unknown). 



Sixth abdominal segment with two pairs of acute teeth from the lateral 

 margin (fig. Ik), but the segment is not divided into two sections by any suture. 

 Uropods with the endopod slightly ()\erreaching the telson and a little longer 

 than the exopod, which is not jointed towards the end (fig. 11). Telson (fig. 11) 

 oblong-triangular, with the narrow entl truncate, with lateral spines, and a 

 couple of tlorsal keels. 



Remarks. — This genus is perhaps more allied and similar to Lophogaster 

 M. Sars than to any other genus of the sul)order; from the genus named it is, 

 however, easily distinguished by the shape of the frontal plate, the reduced 

 eyes, the less developed maxillae, the long uropods, etc. As to the use of the 



