418 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL.14 



Parasmittina crosslandi (Hastings), 1930 



Plate 48, fig. 12 



Smittina crosslandi Hastings, 1930:726. 



Smittina trispinosa, Canu and Bassler, 1930 :27 (in part). 



Zoarium variable in form, the primary layer often broadly encrusting, 

 the secondary, multilamellar growth nodular and frequently rising to 

 form rounded, crooked stems, which branch irregularly; scarcely any 

 two colonies entirely alike in form. 



Zooecia of the primary layer rather regularly arranged in quincunx, 

 elongate-hexagonal or somewhat quadrate, distinct with a raised sepa- 

 rating line, average length 0.45 mm (0.40 to 0.65), width about 0.30 

 (0.25 to 0.40) mm. In the secondary layers the zooecia vary greatly 

 in form and arrangement. The frontal is a granular pleurocyst with a 

 row of rather large areolar pores around the margin. The primary 

 aperture is rounded, more transverse on the proximal border, with well 

 developed cardelles and moderate lyrula which is long and truncate at 

 the tip; width 0.10 or 0.11 mm. The secondary aperture is "spout- 

 shaped," the peristome high on the sides, descending toward the distal 

 border and with a deep narrow "sinus" on the proximal border, the 

 lateral wall sometimes slightly folded in older zooecia. In marginal 

 zooecia 3 to 5 oral spines are often present. The avicularia are various, 

 small or large long-pointed ones near the aperture and directed proxi- 

 mally, small ligulate ones beside the aperture, and small to large oval 

 ones on the frontal, all directed proximally; there is much irregularity 

 in their occurrence, but the small ligulate ones are the most characteristic. 



The ooecia are rounded, prominent, with numerous small pores, the 

 base surrounded by a moderately thick collar, and the peristome is con- 

 tinued in a thin ridge above the orifice. 



The species was described from Taboga Island, Panama, and also 

 listed from Gorgona, Colombia, and the Galapagos Islands. The S. 

 trispinosa of Canu and Bassler, from the Galapagos, at least in part, 

 belongs under crosslandi. 



Hancock Stations: 24 stations about the Galapagos Islands, with 

 numerous others shorewise northward from Colombia to the Gulf of 

 California. The most northerly record is Station 277, Tiburon Island, 

 28°43'45"N, 112°15'30"W. It is the commonest species of the genus 

 within this range, from near shore to more than 100 fms. 



