GLYCERIDAE. 343 



the postsetal lip being but weakly indicated. D. australiensis (Mcintosh) 

 differs from the present species in having the palpi much shorter relatively to 

 the tentacles, and in the greater length and more numerous articles of the latter, 

 the form and proportions of palpi and tentacles in this species much suggesting 

 those of D. filicornis (Grube) from Singapore ; the anterior margin of the man- 

 dibles are smooth or nearly so, lacking the conspicuous, hook-like, teeth of crassa; 

 in the form of the maxillae, the hooks of which are proximally toothed; in having 

 a distinct terminal joint to the notocirri; and in the detailed structure of the 

 setae. D. brevispinis (Grube) from Singapore is a much smaller species than 

 crassa and has distinct terminal joints to the notocirri. D. crassa agrees with 

 D. australiensis and, among others, with D. rubrovittata (Grube) (erucaeformis 

 (Malmgren)) in having a conspicuous, median dorsal, nuchal papilla. 



Glyceridae. 



In this family the body is elongate, cylindrical and often slender, tapered 

 at the ends, and is composed of numerous somites. The coloration is not con- 

 spicuous, being pale and uniform. Species often appear reddish because the 

 blood shows through the integument, this being colored red by large coelomic 

 corpuscles which contain haemoglobin. 



The prostomium is in the form of an elongate cone, which is strongly annu- 

 lated and bears at or near its apex four small tentacles. The basal ring is much 

 longer than the others. Eyes may be either present or absent. 



A retractile nuchal organ, sometimes spoken of as a "palpus," occurs on 

 each side at the base of the prostomium. 



The somites in general are composed of two or more annuli. The parapodia 

 are all of one form throughout the body, and either unu-amous or bkamous. 



Notopodial setae, when present, are simple, typically narrowly limbate and 

 marginally serrate. The neuropodial setae are composite, with the distal append- 

 age acutely tipped and serrate along the edge. 



Branchiae may be either present or absent; when present either sunple or 

 branched (bifurcate). 



Nephridia with inner end closed and in connection with groups of soleno- 

 cytes. 



The proboscis is a strongly muscular and protrusible organ which is glandu- 

 lar at its base and is armed normally with four similar chitinous hooks, or jaws, 

 and bears distally eighteen papillae, of which one is middorsal and one mid- 



