470 BALANlDiE. 



crests and articulations, by the varying form of the shell : 

 I have even seen specimens with the scutum and tergum 

 on one side twice as large as on the other side. 



13. CnAMiEsiPHO — Nov. Genus* PI. 19. 



Compartments four, with the sutures often much oblite- 

 rated: basis membranous. 



Distribution, Australia, China (?). Attached to littoral shells and rocks. 



The two species united under this genus agree in 

 having only four compartments, and in these having a 

 strong tendency to become confluent ; but they resemble 

 each other hardly in any other respect, more than do 

 all the species of the present sub-family. Cham&sipho 

 eolumna differs from all the other Chthamalinae in the 

 structure of its second pair of cirri, and C. scutelliformis 

 differs from all in its shell, — namely, in the small size of the 

 rostrum, with its alas but little developed, and in the very pe- 

 culiar apertures in the three other compartments. Hence this 

 genus can hardly be considered a very natural one, though 

 I could not introduce the two present species into Chtha- 

 malus, or into any other genus, without doing still more vio- 

 lence to the principles of classification followed throughout 

 this work. Chamsesipho bears nearly the same relation to 

 Chthamalus, as Tetraclita and Elminius do to Balanus. 



1. CjiaMjESipho columna. PI. 19, fig. 3 a — 3 c. 



Lepas columna. Spengler. Skrifter Naturhist. Sclbskabet, b. 1, 



(1790), Tab. C, fig. 6. 



Sutures, excepting during early youth, generally oblite- 

 rated both externally and internally : tergum with small 

 pits for the attachment of the depressor muscle. 



* X«juai, on the ground, and aifiov, a tube. 



