54 
THE VOYAGE OF H.M.S. CHALLENGER. 
II. Microsclere§ absent. 
Habitat . — Station 57, “Porcupine” Expedition between Scotland and the Faeroe 
Isles, 632 fathoms (Carter). Station 286, Norwegian Expedition; lat. 72° 57' N., long. 
14° 32' E, 447 fathoms ; bottom temperature, 0°‘8 C. ; bottom, clay (Hansen). 
Remarks . — This is an excellent species, differing from Craniella cranium, not only in 
the absence of sigmaspires, but more particularly in the singular and striking character of 
the protriaene, which has been well described and illustrated by Carter. The cladome of 
the anatriaene is also very different in form from that in Craniella cranium, its cladi being 
much longer and more divergent. Carter’s suggestion that the form of the protriaene is 
the result of disease cannot be entertained. 
Craniella insidiosa, 0. Schmidt. 
Craniella insidiosa, 0. Sch., Spong. Atlant. Gebiet., p. 67, pi. vi. fig. 11, 1870. 
Habitat. — Florida; depth, 17 fathoms. 
Remarks . — This species is insufficiently characterised. I have not been able to 
obtain specimens for examination. 
Craniella lens, 0. Schmidt. 
Craniella lens, 0. Scb, Spong. Atlant. Goblet., p. 67, pi. vi. fig. 10, 1870. 
Spicules. — I. Megascleres. 1. Somal oxea, 3*3 by 0'05 mm. 2. Cortical oxea, 
0‘96 by 0'04 mm. 3. Protrisene, rhabdome 5*18 by 0’03 mm. ; cladi about 0T7 mm. 
long. 4. Anatrisene, rhabdome about 0'045 mm. in diameter. 
II. Microscleres. None are present on the shde presented by Schmidt to the British 
Museum. 
Habitat. — Florida; depth, 135 to 152 fathoms. 
Remarks .. — I give the dimensions of the spicules on the slide mounted by Schmidt as 
a contribution to our knowledge of this species. By itself this is quite insufficient to 
determine the species, and Schmidt’s description is of no value whatever. The species 
must therefore remain doubtful till some one is fortunate enough to obtain access to the 
type. It appears to resemble Craniella simillima, Bowerbank. 
Craniella tethyoides, 0. Schmidt. 
Craniella tethyoides, 0. Scb., Spong. Atlant. Gebiet., p. 66, pi. vi. fig. 9, 1870. 
Spicules. — I. Megascleres. 1. Oxea. 2. Protrisene {?). 3. Anatrisene, cladi 0'07 to 
0'09 mm. long, chord 0’08 to O'Oll mm. 
