THE SESSILE BARNACLES. 259 



TETRACLITA RADIATA (Blainville). 



Plate 01, tigs. 3-3c, 4. 



1854. Tetravlita radiata Blainville, Dabwin, Monograph, p. 313, pi. 11, 

 figs. 5ar-5d. 



Distribution. — West Indies ( ? also Ncav South Wales and Suma- 

 tra). 



This was described by DarAvin as follows : 



Shell white, with numerous approximate longitudinal ribs; radii hroad, with 

 their sununits slightly oblique, internally porose ; tergum with the articular ridge 

 extraoi'dinarily prominent, with the spur not joined to the basiscutal angle. 



The white color, the naiTowly and closely ribbed parietes, and the broad radii 

 give this species an aspect by which it can be easily recognized. 



The large size of the tergum in comparison with the scutum is a 

 further characteristic mark of this species. Unlike most Tetraclitas, 

 it has often been found on ships. 



Specimens in the United States National INIuseum were found grow- 

 ing on Balanus tinthirutbulum antlllensis^ Cat. No. 2031, taken from 

 the bottom of a Cape Cod whaler from the West Indies. There are 

 others in the collection of the Academy of Natural Sciences of Phila- 

 delphia from St. Thomas. 



TETRACLITA COSTATA Darwin. 

 1854. TctracUtd co.'iiata Darwin, IMonograph, p. 330, pi. 11, tigs. 2a-2c. 



Type. — British Museum, from the Philippine Archipelago. 



Specimens are in the collection from " East Indies," Isaac Lea col- 

 lection, and Tataan Island, Tawi Tawi group of the Sulu xVrcliipelago, 

 Alhafroas. 



TETRACLITA CCERULESCENS (Spengler). 



1790. Lepas coenilescens kSpenglee, Skrivter af Naturhistorie Selskabet, vol. 



1, p. 191. 

 1854. Trtraclita cccrulcscens Spengler, Dakwin, IMonograpli, ]•. .". I'J, pi. 11, 



figs. 4a-4(l. 



Tataan Island, Tawi Tawi group of the Sulu Archipelago, Alba- 

 tt'oss. Zamboanga, Mindanao, E. A. Meariis. 



TETRACLITA VITIATA Darwin. 



1854. Tctraclita vitinta Darwin, IMonograph, p. 340, pi. 11, figs. 3a-3e. 



Tataan Island, Tawi Tawi group, Sulu Archipelago, xllhatross. 



TESSEROPORA, new subgenus. 



Tetraclita with a single row of parietal pores. 



Type. — 2\ rosea Krauss. 



Darwin has noted that the pores in the walls of Tetraclitie become 

 more numerous with age, and at a vei-y young stage there is but one 

 row. The recent species for which this subgenus is proposed, is to be 



