140 MR. CYRIL CROSSLAND ON THE [June 16, 



if only one specimen occurred in the collection, becomes an 

 interesting character when it is found that it occurs in all cases, 

 even in young specimens. Besides the characteristic long capil- 

 laries, short, remarkably broad comb-setae occur in some feet at 

 either end of the body (PI. XV. fig. 10). 



There are four aciculse in the anterior feet, two or three in those 

 of the middle region, and one posteriorly, which may or may not 

 be accompanied by another which is almost colomiess. 



Marphysa simplex, sp. nov. (Plate XY. figs. 11, 12.) 



Two specimens from between tide-marks, near Zanzibar Town : 

 the larger incomplete, measuring 10 cms. by 0-45 cm., composed 

 of 155 segments ; the smaller complete, 15 cms. long by 0-3 cm. 

 broad. 



The circular section of the body is very nearly uniform through- 

 out, and the leng-th of the segments is greater than in the case 

 of the preceding species, and those immediately following the 

 head are neither longer nor narrower than the rest. The body 

 narrows quite gradually to the anus, the opening of which is large, 

 upwardly directed, and provided with a pair of moderately long cirri 

 ventrally. 



The prostomium is bilobed, the median notch being continued 

 dorsally as a narrow groove to its base. The tentacles are nearly 

 twice as long as the prostomium and are delicately ringed. Their 

 insertion, basal parts, and the position of the eye-spots are shown 

 in fig. 11, PI. XV. Ko considerable portion of the prostomium 

 is hidden by the next segment. The peristomium has a total length 

 about equal to that of the head, the segments immediately suc- 

 ceeding being about half as long and of the same size, or nearly 

 so, as those composing the rest of the body. 



The lai-ger pieces of the dental apparatus all show a white 

 edging, especially prominent on the upper ends of the mandibles, 

 which bear large plates of this calcareous matter. The great 

 dental plates bear three teeth each in the larger specimen, four 

 in the smaller. The teeth of the laterals are blunt, and number 

 four and three on the left, six on the right. The whole apparatus 

 presents no peculiarity save the striTcture of the mandibles, for 

 which see text-fig. 14, p. 142. 



The feet are small, and contain numerous long setse, projecting 

 from a seta-sac, the posterior lip of which is very broad and 

 straight-edged (text-fig. 13, p. 141). Ml the setse are smooth, 

 without toothing or borders, the capillaries being bent gently and 

 pointed in the usual way, the articulated pieces of the compound 

 set?e being sword-like and slenderly pointed. The comb-seta? are 

 long and slender, very finely toothed, the outer teeth on either 

 side being considerably the longer. PL XV. fig. 12 represents a 

 group of these setae, showing their variation in the same foot, 

 the distance they project from the seta-sac, &c. They are much 

 lai-ger than the somewhat similar ones of M. macintoshi. 



There are four or five aciculfe in the anterior feet ; three, with 



