134 



seornent of the pedicel of the sixth cirrus. It has 8 quadratic segments ; the first however, is 

 more elongate, as are also the two last ones (PI. XIII, fig. 4). Hairs disposed in a dense group 

 at the inner side near the extremity of each segment and in smaller number at the outer side 

 The hairs at the inner side on the lower segments very long, those on the following segments 

 not quite so long, the hairs disposed lower down reaching nearly as far with their extremities as 

 those of the last segments. Last segment obliquely truncated, with a group of hairs on the tip. 



Penis short, reaching as far as the middle of the second segment of the pedicel of 

 the sixth cirrus. Narrow, bluntly pointed at the extremity. Here and there a single hair disposed 

 on its surface. A young specimen was furnished with a very short penis, the length of which 

 equalled two-thirds of that of the caudal appendage. 



This species was collected by H. M. S. "Siboga" at the following places: 



Stat. 88. June 20, 1899. Lat. o°34'.6N., Long. U9°8'.5E. Dcpth 1301 m. Bottom: fine grey 



mud. About six specimens, some of them very large. 

 Stat. 262. December 18, 1899. Lat. 5°53'.8S., Long. I32°48'.8E. Depth 560 m. Bottom: solid 



bluish-grey mud. Two specimens, one attached to a Hexelasma, the other to 



a small stone. 

 Stat. 297. January 27, 1900. Lat. io°39'S., Long. i23°4o' E. Depth 520 m. Bottom: soft grey 



mud. One specimen, attached to the shell of a Gastropodous mollusc. 



General Remarks. This species resembles Verruca magna Gruvel, from the Gulfof 

 Gascogne. As the articular ridges of the moveable valves of the two forms are slightly different 

 and as the rostrum and carina of the Siboga-animals are much larger than in V. magna, I 

 have thought it better to clescribe the form occurring in the Malay Archipelago as a distinct 

 species. It is certainly nearly related to the Atlantic form. 



2. Verruca naviada n. sp. PI. XII, tïg. 4 — 6. PI. XIII, fig. 5 — 7. 



Shell not depressed, plan of the moveable valves vertical to the basis. Moveable valves 

 large, the scutum with 5, the tergum with 7 articular ridges. Apex of the carina slightly pro- 

 duced, rounded, that of the rostrum hardly produced, but also rounded. Carina and rostrum 

 having one longitudinal rim and articulating with one another with a single tooth. Fixed scutum 

 and tergum relatively large, having a great elevation and articulating with one another by 

 means of two articular ridges. 



This beautiful species (PI. XII, fig. 4 and 5) is characterised in the first place by the 

 great number of articular ridges on the moveable valves, and in the second place by the high 

 elevation of these valves and of the fixed scutum and tergum also. The rostrum and carina are 

 on the contrary more developed in breadth than in height. On all the parts of the shell the 

 lines of growth are very distinct ; the surface of the fixed tergum and scutum and of the 

 rostrum and carina is furnished, moreover, with very characteristic folds, the direction of which 

 is perpendicular to that of the lines of growth. 



This species is represented in the Siboga collection by two specimens, of which, however, 

 one only can be considered as full-grown. 



The moveable scutum has the apex clistinctly beaked and projecting freely. lts shape 



6 



