METALIA DICRANA. 211 



are the less is their amount of contact at tip, the smallest ones being in contact 

 nearly the full length of the blade. Rostrate pedicellariae occur, having valves 

 .60-.80 mm. long; these valves have the bases about 25 per cent higher than 

 wide and the blades a little expanded at tip. 



The Albatross collection contains seven specimens, of which six are from 

 an unknown locality, but probably somewhere on the Lower Californian coast. 

 The seventh is from Pichilingue Bay, Lower California. There is also a frag- 

 ment of ambulacrum I and interambulacrum 5 from a specimen, which must 

 have been about 120 mm. long, estimated by comparison of fragment with 

 the same area in a complete adult. This is an exceptionally large size for this 

 species. The fragment was taken at station 4149, off Modu Manu, Hawaiian 

 Islands, in 33-71 fms. 



Metalia dicrana, 1 sp. nov. 

 Plates 146, fig. 16; 160, figs. 1-4. 



Length of test, 58 mm.; width at middle, where widest, 53 mm.; height 

 at middle, where highest, 37 mm., but at apical system only 31 mm. The 

 corresponding measurements of the bare test figured (PI. 160, figs. 1-4) are 

 62, 55, 39 and 32 mm. A much smaller specimen is relatively higher, its 

 measurements being 40, 36, 27.5, and 24 mm. The form of the test is similar 

 in all three specimens and will be readily understood from the figures (PI. 160, 

 figs. 1-4)' The apical system is very far forward and reveals four large genital 

 pores. The anterior ambulacrum (III) is nearly or quite flush dorsally but is 

 slightly sunken at the ambitus. Petals II and IV have about twenty pore- 

 pairs on each side and are about 20-22 mm. long. They run out at direct right 

 angles to the long axis of the body. Petals I and V have 25 or 26 pore-pairs 

 on each side and are some 28 mm. long. They are divergent from the start 

 at an angle to each other of about 50°-55°, and primary tubercles occur in 

 interambulacrum 5 close up to the madreporite. The peripetalous fasciole is 

 well marked, though it is so indistinct in the photograph (PI. 160, fig. 1). Its 

 course shows some diversity in the three specimens; in general it may be said 

 that there is a small but sharp and distinct re-entrant angle in interambulacra 

 2 and 4 and a somewhat larger one just posterior to petals II and IV, while 

 across interambulacrum 5, the fasciole is distinctly arched towards the apex. 

 The periproct is large, 10 mm. high by 7 mm. wide, and is situated near the 



1 ALpavos = two-pointed, in allusion to the posterior end of the sternum. 



