Mr. E. J. Miers on Malaysian Crustacea. 457 



presents the tessellated appearance ; h, tesseral division, much 

 magnified, to show microspinous processes (diagrams). 

 Fig. 8. Hydradendrium spinosum, n. gen. et sp., natural size of specimen. 

 a, growth of dendriform spines (see g) ; b, portion of stem, 

 much magnified, to show rows of spines, viewed laterally ; 

 c, horizontal section of stem and spines, to show that the stem is 

 composed of concentric laminae developed on d, the axial canal, 

 from which pari passu are developed the spines : scale l-48th to 

 l-1800th inch, e, spine, much more magnified, to show that it 

 also is composed of concentric laminae, but solid and imperforate 

 towards the free end ; f, end of branch, to show commencement 

 of spinal development on the medullary sarcode : scale l-24th 

 to l-1800th inch, g, dendriform growth of spines produced by 

 the coenosarc (see a) : scale l-48th to 1-] 800th inch. 



[To be continued] 



XLI. — On a Collection of Crustacea from the Malaysian 

 Region. — Part IV. Penssidea, Sto/uatopoda, Isopoda, Suc- 

 toria, and Xvphosura. By Edwakd J. MlERS, F.L.S., 

 F.Z.S. 



[Plate XV.] 



[Concluded from p. 884.] 



Penjeibea. 



Penceus avirostns, Dana. 



W. Borneo. 



I refer to this species two female specimens of Penceus in the 

 collection. They agree with Dana's description in the form of 

 the rostrum, fifth ambulatory legs, &c. In both the rostrum is 

 prolonged backward into a somewhat indistinct median dorsal 

 carina, which, however, is obsolete near the posterior margin. 

 The rostrum, in the only perfect specimen, is 7-toothed 

 above. 



This species was not represented in the Museum collection 

 when I wrote my analytical table of the species of Penceus 

 (P. Z. S. 1878, p. 306) ; and the examination of the foregoing- 

 examples shows that it should be classed (in that synopsis) in 

 the neighbourhood of P. monoceros and P. Dobsoni, on account 

 of the distinct dorsal ridge of the carapace. 



Penceus scutytilis, Heller. 



W. Borneo (a female). 



This specimen agrees very well with the description and 

 figure of Heller, based on examples from Java. Like the 



