232 WALTER GARSTANG. 



EXPLANATION OF PLATES 12—14, 



Illustrating Mr. W. Garstaug's paper ou ^' Some Modifications 

 of Structure subservient to Respiration in Decapod Crus- 

 tacea." 



PLATE 12. 



Fig. 1.— Calappa grauulata, Fabr., from the Mediterranean. Front 

 view, showing the closure of the chelipeds beneath the carapace and the 

 respiratory orifices above them. a. Exhalant orifice, b. Branch of endo- 

 podite of first maxilliped, forming opercular floor of exhalant canal, c. 

 Antero-lateral margin of carapace. d. Dentated crest on propodite of 

 cheliped. e. Inhalant orifice of exostegal canal. /. Second antenna, forming 

 part of orbital wall. 



PLATE 13. 

 Fig. 2. — Matuta picta, Miers, from Diego Garcia. View from above, 

 the anterior part of the crab's body being elevated to display the buccal 

 region, a. Exhalant orifice, b. Third maxilliped. c. Carpet of hairs on 

 pterygostomial plate, d. Propodite of cheliped. e. Orbital gutter, having a 

 ventral floor of interlocking hairs. /. Postero-lateral extension of orbital 

 gutter on pterygostomial plate. 



PLATE 14. 



Fig. 3 «. — Corystes cassi velaunus from Plymouth. Frontal area, 

 showing tube formed by second antennae (dorsal view). 



Fig. 3^. — Corystes cassivelaunus from Plymouth. Ventral view, 

 showing floor of prostomial chamber. 



Fig. 4«. — Albunea symnista, Fabr., $, from Madras. Dorsal view, 

 showing tube formed by first antennae, and the ocular plates which form the 

 roof of the prostomial chamber. 



Fig. 4i. — Albunea symnista, ? , from Madras. Ventral view, show- 

 ing basal part of antennular tube, lamellate terminal expansions of first 

 maxillipeds, and the pediform second and third maxillipeds. 



Fig. 5. — Albunea scutelloides, n. sp., ^, from Sulu Sea (Oxford Mu- 

 seum). Dorsal view. The antennules are pulled slightly forwards, showing 

 the prostomial chamber beneath. Also showing the double bend of the basal 

 joints of antennules and the broad elliptical optic plates, and eye-spots. 



N.B. — The figure does not represent the median emargination as deep as 

 is actually the case. The small admedian teeth, situated on the outer sides 

 of the optic plates, are also inadvertently omitted. 



