294 BARNACLES FROM DEEP-SEA CABLES. 



relationship. My attention was first drawn to the close affinities 

 of the two forms by the Rev. T. E. R. Stebbing, F. R. S. Two 

 years later Hoek referred specimens from the Malay Archipelago 

 to two new varieties, which he called robusta and gemma. Tlie 

 type of 8. inerme differs from one of his specimens of the variety 

 gemina hardly more than these specimens vary among themselves. 

 Hoek's Malayan examples differ considerably from those hitherto 

 described from Japan, in particular in the great development of 

 the peduncle and the capitular investment. I have, however, been 

 able to examine a good series both from Japan and from the Malay 

 Archipelago and cannot find any distinct break either between 

 specimens from different localities or between those of the supposed 

 varieties. 



There are in the Indian Museum four specimens from Japan. 

 Two of these, which were received in exchange from the British 

 Museum, are comparatively small, the capitulum of the larger 

 example being only about 25 mm. in length. They agree sufficient- 

 ly w T ell with Pilsbrv's and Fischer's figures and differ little, apart 

 from size, from the young specimen of the variety robusta figured 

 by Hoek, except that all the prominent valves are a little more 

 pointed. I recently obtained in Japan two very large specimens 

 which have the following measurements : — 



Height of capitulum 

 Breadth of capitulum 



Thickness of capitulum . . 

 Length of peduncle 

 Diameter of peduncle 



In measuring the breadth of the capitulum I have not in- 

 cluded the prominent part of the carinal latera; I have measured 

 the thickness of the capitulum at the base. 



These two specimens, which were taken side by side, agree 

 much more closely with the description and figures of the variety 

 robusta than they do with those of the typical form. The invest- 

 ment of their capitulum is thick and semi-opaque and their 

 peduncles, though less swollen than those of the type of robusta, 

 are very nearly as long. I do not think, therefore, that the Japanese 

 form can be regarded as a local race of the Malayan one and I see 

 no reason for giving the latter a distinct name, so far as well calci- 

 fied examples are concerned. 



My supposed species Inerme differs from the typical form and 

 from robusta merely in the rather shorter peduncle and in the 

 extreme degeneration of the capitular valves, for the anatomical 

 differences noted by Pilsbry are certainly not beyond the limits 

 of variation. In respect to the degeneration of the valves it is 

 merely an extreme form of Hoek's form gemina, one of the co-types 

 ■of which is now in the Indian Museum. There is in the Raffles 



Jour. Straits Branch 



A 



B 



63 mm. 



55 mm. 



43 „ 



35 „ 



26 „ 



22 „ 



62 „ 



49 „ 



25 .. 



22 



