259 



teeth 2 and 3 are laterally doublé, and tooth 4 which is single has two smaller teeth situated 

 near ils base. 



Maxi 11a with the edge nearly straight, a rudimentary notch in which two hairs are 

 disposed under the two larger upper spines, and a dozen somewhat smaller spines varying 

 in length, along the remaining part of the edge; near the lower angle a group of half- 

 a-dozen hairs occupy the lowermost part of the edge. Numerous hairs are disposed on 

 the surface of the maxilla and near the outer edge, extending to between the spines along 

 that edge. 



Outer m a x i 1 1 a e distinctly bilobed ; upper lobe broadly-oval, with a very dense tuft of 

 curved hairs disposed at the tip and over the inner half of the surface ; inferior lobe elongate, 

 with the inner margin convex and hairs covering only the inner half of the surface. 



Cirri. Cirrus of first pair with very unequal rami, the longer ramus havfng 19, the 

 shorter only 7 segments; in both rami the lower segments are much broader than the more 

 distal ones : hence the shape of the whole ramus is elongately-conical. The segments of the 

 longer ramus are in general short, only slightly increasing in length towards the extremity; 

 those of the shorter ramus are all of about the same length. The length of the shorter ramus 

 is more than half the length of the longer. A great number of the spines, on the 4 to 5 

 lower segments, are disposed in both rami on a swelling of the surface situated near the 

 distal extremity of each segment. 



Cirri of the second and third pairs of about the same structure, which is quite different 

 from the 4 th to 6 th cirrus. The second has 8 and 9, the third 10 and 13 short quadrate 

 segments which are slightly swollen near the distal extremity, and are somewhat narrower near 

 their basis. A group of larger spines is situated on the swelling at the inner side and near 

 the upper margin, a very dense bush of shorter and stronger spines on the swelling at the 

 outer side of each segment. 



The 4 th to 6 th cirri have elongate segments ; only one of the pairs of spines disposed 

 in the ordinary way along the inner margin of each segment is well developed : the spines 

 of this pair are long but relatively delicate. Yet a second pair of very small spines and a 

 third pair of quite rudimentary ones can be made out as a rule. The number of segments is 

 very large : 29 and 33 for example in the 6 th cirrus of the specimen I dissected. 



The penis is very long and grows narrower towards the free extremity; it is com- 

 posed of numerous short rings, and it has short hairs scattered nearly over the whole length. 



The small straight project ing po int at the dorsal basis of the penis is rela- 

 tively large, curved at its dorsal side and has a blunt, not pointed tip. 



2. Pyrgoma kuri n. sp. PI. XXYII, fig. 1 — 2. 



Shell short-cylindrical, with the upper part feebly conical, coloured greenish-brown ; 

 orifice elongately-oval, narrow; scutum and tergum calcified together, a suture showing their 

 limits; scutum with a prominent occludent ledge and a well-defined adductor plate, tergum well- 

 developed, with the spur longer than the remaining part of the valve. 



131 



