An accessory cusp occasionally appears between mesial buccal (Paraconus) and distal buccal cusps (Metaconus) of the upper molars of Macaca. BATUJEFF had already given attention to such kind of cusp (1893) and DE TERRA had reported this accessory cusp under the name of " interstitieller Grübchenhöcker" without detailed description (1905).
The author would like to name this accessory cusp as"the median buccal accessory cusp (Bucciconulus intermedius)" to indicate its location and to discriminate it from Parastyle etc derived from the buccal cingulum of the upper molar.
Configurations of the median buccal accessory cusp were investigated on 157 first molars, 152 second molars and 105 third molars out of 304 upper molar rows of Macaca irus. Additional examinations were made on the upper molars of Macaca mulatta, Macaca radiata, Macaca maura and Macaca cyclopsis for reference. All the inspections were carried out with a magnifying-glass (25 X).
The results obtained are as follows:
The median buccal accessory cusp is considered to be an accessory cusp found on the upper molars of Macaca in general.
As far as the upper molars of Macaca irus are concerned, 19 first (12.1%), 22second (14.5%) and 22 third molars (21.0%) had cusps of this kind.
Out of upper molars of Macaca irus having the above mentioned accessory cusp, 9 first, 13 second and 13 third molars had the accessory cusps located exclusively on the occlusal surface (Occlusal type), while 10 first, 9 second and 9 third molars had such an accessory cusp located on both occlusal and buccal surfaces spreading along the buccal groove (Occlusal-buccal type). The groove separating the accessory cusp from the distal buccal cusp is deeper and more distinct than that between the accessory cusp and the mesial buccal cusp. Accordingly the former must be the buccal groove itself. This might explain that the accessory cusp is located mesial to the original buccal groove, and is a part of the menial cusp of the upper molar.

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1. In the Jomon Period, Neolithic culture of Japan, 495 fish-hooks have been recovered from 77 sites, of which 430 are one-piece hooks, and 65 two-piece hooks. However, no composite hook has ever been found.
2. One-piece hooks are classified into six types: (1) non-barbed; (2) out-barbed; (3) in-barbed; (4) both-barbed; (5) stem-barbed; (6) anker-type, and of these hooks non-barbed and out-barbed are most popular. In other words, it may well be said that these six types can be classified into two groups such as non-barbed (Type 1) and barbed (Type 2-6). In general, it can be said that the former, taking the form of medium size (3-5 cm.), has been found throughout the Jomon Period and widely distributed. The latter, however, has made a remarkable progress since the later phase of the Stage 3 (i, e. Jomon Period is divided into five stages), and includes many large-sized specimens beside the medium-sized ones. At the same time, it must be remembered that the increase of the absolute quantity has become more conspicuous, though its distribution is comparatively limited.
3. Two-piece hooks are classified into six types (A-F). Unfortunately, we are obliged to make a study of mainly Types A, E and F because of the lack of the specimens of the other types. Type A found during the Stage 1 comprises chiefly the medium-sized two-piece hooks which are similar to the non-barbed type of one-piece hook in their size, and Type E and F consist of large- or remarkably large-sized specimens. Hence it can be said that Types E and F are a sort of form that promoted progressively the tendency to make larger fish-hooks like the barbed type of one-piece hook.
4. A study of fish bones found in the shell mounds provides us with information that fish-hooks were mainly used for the capture of such fishes as Pagrosomus unicolor (QUOY & GAIMARD), Euthynnus pelamys (LINNÉ) and Thynnus thynnus (LINNE), though the last is rare. It seems safe to suppose that the fish-hooks of medium size might correspond to the use of the capture of Pagrosomus unicolor, and those of large size to Thynnus thynnus: in particular the latter seems to have been bartered as a major materials.
5. It may be explained that the phenomenon that fishery by angling, which had been developed since the later phase of the Stage 3, was more positively selecting fishing places in the Stage 5 indicates the appearance or development of a group of houses specializing in the fishery.
6. 96.6 per cent of fish-hooks are made of deer antler, and the Types E and F of two-piece hook are of ideal perfection of technical development which has succeded in meeting the demand of mass production of the large-sized fish-hooks within the restriction of the material-antler. However, this restriction of the material seems to have been dissolved by the diffusion of Yayoi culture in the succeeding period.
7. Such a technical development was made along the Pacific coast of northeast Honshu, where the sign of this advance had been recognized in the later phase of the Stage 3, and especially in this coast the Bay of Sendai must have played a leading part in making a remarkable progress.
8. From the extensive point of view, the sites containing the fish-hooks are concentrated along the Pacific coast of central and northeast Honshu, and are very rare in the prefecture bordering the Japan Sea and in southern Honshu and Hokkaido. It is noteworthy that the areas of heaviest concentration of the sites from which the fish-hooks have been recovered corresponds to the areas where the Jomon culture most flourished.

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