BARNACLES OF JAPAN AND BERING SEA 
83 
texture and finer sculpture the plates are similar; so that I can not doubt that the forms are related. 
Unfortunately the number of plates of the wall is not knowm in the Hawaiian species, since only frag- 
mentary remains were preserved; yet so far as these go they indicate an octomerous wall, the median 
latera of which are still unknown. The development of an accessory basal whorl of plates in C. darwini 
indicates affinity to the genus Catophragmus. I am disposed to believe that when perfect individuals 
come to light, C. darwini will prove to belong to a distinct genus, or at least subgenus, intermediate 
between Pachylasma and Catophragmus, and distinguished from Catophragmus by the well-developed 
caudal appendages, the wall with a single series of accessory basal plates, part of them with alae, and 
by the dense, porcellanous texture of all the plates. This group may be called Chionelasmus . 
EXPLANATION OF PLATES. 
PLATE VIiI. 
Fig. 1, 4. Scalpellum rubrum Hoek, lateral and dorsal views of an adult, no. 38680, U. S. National Museum, x 4.7. 
Fig, 2. Scalpellum rubrum, rostrum and adjacent parts. 
Fig. 3. Scalpellum rubrum , rostrum and adjacent latera seen from the inside. 
Fig. 5-7. Conchoderma auritum Linnaeus, posterior, ventral and lateral views of living specimens from Plover Bay, 
Siberia Drawn by Wm. H. Dali. 
plate ix. 
Fig. 1. Scalpellum stearnsi Pilsbry. Young individual, no. 38678, U. S. National Museum, x 6. 
Fig. 2, 3. Scalpellum gonionotum Pilsbry. Lateral and dorsal views of the type.no. 38678, U. S. National Museum x 10. 
Fig. 4 Scalpellum gonionotum. Rostrum and adjacent plates. 
Fig. 5, 6. Scalpellum wellnerianum Pilsbry. Lateral and dorsal views of the type, no. 32679, U. S. National Museum, x 9. 
Fig. 7. Scalpellum wellnerianum. Rostrum and adjacent plates. 
PLATE X. 
Scalpellum japonicum Hoek. 
Fig. 1, 2. Lateral and dorsal views, no. 38684, U. S. National Museum, x 4- 
Fig. 3. Rostrum of the same individual. 
Fig. 4. 5. Lateral view and rostrum of another individual from the same station, x 4, no. 38685, U. S. National Museum. 
Fig. 6, 7. 8. Ventral, dorsal, and lateral views of a very young Scalpellum of the japonicum type, x 12.7, no. 38688, 
U. S. National Museum. 
Fig. 9. Outline figure of the type specimen of S. japonicum, x 5 Y2. 
PLATE XI. 
Fig. 1.. 2. Scalpellum japonicum biramosum Pilsbry. Right and left lateral views of the type specimen.no. 38686, U. S. 
National Museum, x 3. 
Fig. 3. Rostrum and adjacent parts of the same individual. 
Fig. 4, 5 Scalpellum molliculum Pilsbry. Lateral view (x 3) and rostral detail of the type, no. 38687, U. S. National 
Museum. 
Fig. 6, 7. Oclolasmis orthogonia Darwin, no 38676. U. S. National Museum. Two varieties from off Kagoshima Gulf, 
x 8.6. 
Fig. 8, 9. Heteralepas sp. undet. Ventral and lateral views, x 6, no. 38682, U. S. National Museum. 
PLATE XII. 
Fig. 1-3. Heteralepas vetula Pilsbry. Dorsal, lateral and ventral views of the type, no. 38689, U. S. National Museum. 
Fig. 4 - Balanus rostratus aperius, no. 38670, U. S. National Museum, natural size. 
Fig. 5. Balanus callistoderma Pilsbry, walls of type, natural size. 
Fig. 6. Balanus rostratus Hoek, Tokyo Harbor, Japan.no. 1814. Academy of Natural Sciences, Philadelphia, natural size. 
Fig. 7. Balanus rostratus aperius Pilsbry, no. 38667, natural size. 
PLATE XIII. 
Fig. 1. 2. Balanus rostratus apertus Pilsbry. Scutum of no 38667, U. S. National Museum. 
Fig. 3, 4. Balanus hoekianus Pilsbry, scutum of type. 
Fig. 5. Balanus hoekianus Pilsbry. Profile of scutum of type. 
Fig. 6. 7. Balanus hoekianus Pilsbry, tergum of type. 
Fig. 8, 9. Balanus rostratus aperius Pilsbry, tergum of no. 38667, U. S. National Museum. 
