REPORT ON THE CRUSTACEA MACRURA. 



233 



" C. Mature zoea. Letters as before. Length 2 mm. North of New Guinea and 

 on the voyage along the Marianne Islands. 



"All seen 'on the ventral surface. 55 xnat. size. H. ^." 



Claus, in his Crustaceen System, 1 pi. ii., gives three figures of what he states 

 to be the Zoea of Penasits, the second figure representing only the pleon. The telson 

 corresponds with that in Willemoes-Suhm's figure (fig. 43), which agrees in °-eneral 



Fig. 43 (C).— Zoea of Sergestes tenuis (?). From a drawing by Dr. v. WiUemoes-Suhni. la, Anterior lip ; mdb, mandibles ; mx\ first 

 maxilla ; mx", second maxilla ; mxp, maxilliped ; g\ first gnathopod ; pr, pereion ; pi, pleon. 



structure with Claus's fig. 1, excepting that Willemoes-Suhm's animal has peduncu- 

 lated eyes and a frontal rostrum, whereas Claus's has the ophthalmopoda sessile, 

 without any evidence of a rostrum, and as Claus says that his fig. 2 is the same 

 as fig. 1, only larger, we must presume that it also has the ophthalmopoda in an 

 undeveloped condition, whereas his fig. 3 shows the ophthalmopoda largely developed, 

 and the posterior pair of pleopoda also in an advanced condition. There is, however, 



1 Untersuchungen zur Erforschuug der genealogischen Grundlage des Crustaceen-Systems, 114 pp., 19 pis. Wien, 1876. 



(ZOOL. CHALL. EXP.— PART LII. 1886.) Fff 30 



