27 



dite (P.) and dactylopodite (D.) respectively. Arising 

 from the appendage immediately in front of the base of 

 the nabellum is a podobranch (pod. br.) (see section on 

 Respiratory Organs). 



The Third Maxillipede (PI. II, fig. 11, PL IV, fig. 30) 

 is built on a similar plan to the previous appendage. The 

 basis and the ischium are fused together to form the 

 basi-ischium (B.-I.). The podobrancli (pod. br.) is very 

 small and arises from the coxopodite. The nabellum 

 (flab.) lies on the lower part of the thoracic epimera below 

 the gills. The endopodite and exopodite (ex.) are closely 

 applied together and are much flattened so as to form 

 with the same appendage of the other side an effective 

 operculum closing over the remaining mouth parts, and 

 preventing the exhalent current of water from the 

 branchial chamber from passing out except in front of the 

 scaphognathite. 



The mandibles, maxillae and maxillipedes all lie 

 around the month in the large depression between the 

 anterior parts of the sub-branchial regions of the 

 carapace. The ventral side of the third maxillipedes is 

 on a level with the sub-branchial region. As the 

 nabellum of this appendage passes back into the branchial 

 cavity, it passes along the front of the anterior inhalent 

 branchial aperture, and reduces the size of the aperture 

 considerably. At this point the nabellum* is also richly 

 clothed with strong setae, which probably act as a 

 "strainer" in conjunction with the setae present on the 

 front part of the coxa of the chela (see section on 

 Respiratory Organs). 



The First Pereiopod (or chela) (PL II, fig. 12, PL III, 



* The coxopodite of the third maxillipede is prolonged outwards, 

 and bounds the inner part of the inhalent aperture. The nabellum 

 bounds the outer part. Both are richly clothed with setae on their 

 posterior faces. 



