138 



MR. CYRIL CROSSLAND ON THE 



[June 16, 



of the body the feet are provided with this and one acicuhim only. 

 The ordinary setfe project considerably, especially in the anterior 

 feet. Here they ai-e arranged in two distinct bundles of simple 

 capillaries dorsally and compound ventrally, with a set of shorter 

 and stouter compound setfe between the two. Posteriorly this 

 arrangement is less definite, the bundles i-unning into one another. 

 The long capillaries are as usual slightly bent, smooth, and end in 

 a very delicate point. Long and slender comb-setfe occur among 

 the more ventral capillaries (PI. XIY. fig. 5) of the posterior 

 segments, the teeth of which, except the two outermost, are hardly 

 to be made out even by the ^-in. objective. The articulated pieces 

 of the compound setae are of the knife-shape. Their proportions 

 are shown in PI. XIY. fig. 5. 



Text-fiff. 12. 



Marphysa macintosM. Mandibular jaw-plates, X 45. 



The gills begin from seg. 32 to 54, attaining their full size 

 more gradually in the former case. Their greatest number of 

 branches may be four, five or, six, of moderate length, i. e. they 

 can be nearly made to meet over the back. Their arrangement is 

 bushy rather than comb-like (PI. XIV. fig. 6). As the gills are 

 present up to the ends of all three fragments, it is most probable 

 that they extend to near the anus. 



All the other species of Marphysa in which an undivided pro- 

 stomium is met with are characterised by the possession of few, 

 and those very large gills. The present species therefore occupies 

 a conspicuous position in the genus, as indicated in the above 

 table. The shortness, slenderness, and insertion of the tentacles, 

 the rudimentary condition of the eyes, and the articulation of the 

 ventral cirri are also prominent specific characters. 



