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 ;. Scalpellum Steamsi Pilsbry var. robusta and var. gemina n. var. PI. VI fig. i — 12. 



Scalpclluni Steamsi Pilsbry is a shallow-water species from Japan. It was described for 

 the first time (1890) by Pilsbry 1 and a year later by Fischer 2 (as Sc. calcariferum). Both 

 Weltner (1. c. p. 250) and Gruvel (1. c. p. 44) consider the species of Fischer as synonymous 

 with that of Pilsbry, and comparing the figures there can be no doubt that they are rio-ht. 



In the Malay Archipelago H.M.S. "Siboga" collected at different Stations and at depths 

 varying from 204 — 450 m., specimens of a Scalpelluiu-species, which at first sight showed oreat 

 resemblance with Pilsbry's Sc. Steamsi. I have been long in doubt, whether they belono- to 

 that species or not. The result of a careful comparison of the specimens of the Malay Archipelao-o 

 with one another and with a specimen from Nagasaki (Japan) has been, that I do not consider 

 them as specifically different, but that the animals collected by H. M. S. "Siboga" must be 

 regarded as two varieties of Pilsbry's species. 



I give in fig. 1, PI. VI, a figure of Pilsbry's Sc. Steamsi from a specimen collected by 

 Lischke near Nagasaki which belongs to the collections of the Berlin Museum of Natural 

 History 3 . It was in dry condition but it corresponded in all regards with the descriptions and 

 figures given by Pilsbry and Fischer. The varieties robusta and gemina differ from the Japan 

 species in several regards as will be shown. 



a. Scalpellum Steamsi, var. robusta. PI. VI, fig. 2, 3, 8 — 12. 



The variety robusta differs at first sight by its much more plump, robust shape and by 

 the length of its peduncle. The Japan form has the capitulum more elongated, its length 

 measured along the occludent margins of scutum and tergum being equal to one and a half 

 times the breadth ; the apex of its tergum is produced ; the length of the peduncle is nearly 

 the same as the breadth of the capitulum and is by all means considerably shorter than the 

 length of the latter. In the variety robusta the length of the capitulum is only once and a third 

 its breadth ; the apex of the tergum is not produced and the peduncle is considerably longer 

 than the capitulum. 



The shape of the different valves in the variety robusta is not very different from that 

 in the original Japan species. Yet the upper latus and the infra-median latus are both considerably 

 broader in this variety and this is also the case with the tergum. The latter valve has the 

 apex and the angle formed by the carinal and scutal margins blunt. 



As in the Japan specimens the marginal parts of the valves are not calcified: if the surface 

 is thoroughly cleaned with a brush, the calcified portion which is white, is easily distinguished 

 from the chitinous marginal parts which border the valves. In the Malayan specimens, however, 

 the calcified portions are not at the surface, the whole valve being covered by a rather thick 

 chitinous coating. Whether this is also the case in the shallow-water form from Japan I cannot 



! Pilsbry, H. A., Description of a new Japanese Scalpclluni. Proceed. Acad. Nat. Sci. Philadelphia. iSgo. p.441 — 443. (Sc. Stearnsi). 



- Fischer, P., Description d'une nouvelle espèce de Scalpellum du Japon. Bullet. de la Soc. Zoolog de France. XVI, 1891, 

 p. 116 — IiS. (Sc. calcariferum). 



3 The director of the Museum, Prof. Karl Möbius, and the Keeper of the Cullection of Crustaceans, Dr. W. Weltner, made 

 the study of these specimens easy and agreeoble to me. 



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