290 University of California Publications in Zoology. [Vol. 4 



This protean species assumes many forms in our waters such 

 that if the extremes only, or isolated specimens are examined they 

 appear to be different species. Transition stages, however, occur 

 between the numerous variations, and it has not been thought 

 best to divide the species. Taking the whole coast from Alaska to 

 San Diego, the delicate, hyaline, strongly reticulated (fig. 43) 

 colonies are more common in the south ; these may or may not 

 have the lateral processes described as var. cornuta by Busk 

 ('54) and Hincks ('80). Even in the south, i.e., south of Point 

 Conception, the thicker walled variety occurs in small quantity. 

 This is frequently strongly reticulated, often has the lateral pro- 

 cesses, and is usually marked by definite transverse lines with an 

 umbo below the orifice ; it sometimes forms colonies of more than 

 one layer, the upper layers of zooecia becoming very irregular in 

 arrangement. North of San Francisco Bay, the thicker walled 

 variety is very abundant. Here the zooecia of the first layer are 

 often much elongated, well separated and with or without retic- 

 ulations; sometimes they are more barrel-shaped, having well 

 marked transverse lines and ridges and frequently a distinct um- 

 bo below the orifice. Since in a study of specimens from the 

 whole coast the marks characteristic of the var. cornuta. and of the 

 species S. discrcta are found mingling together and merging al- 

 most insensibly, there is no sufficient ground upon which to base 

 sub-species and all are reported here under the one name. 



The typical ^S*. hyalina together Avith var. cornuta are reported 

 by both Busk and Ilincks from California. Reported also from 

 Queen Charlotte Islands. Abundant in our collection from Ya- 

 kutat, Alaska, to San Diego,' California, found between tide 

 marks. 



59. Schizoporella insculpta Ilincks. 



PI. 20, figs. 46, 47. 



ScMzoporeUa i)i.^culpta Ilincks, 1882, vol. 10, p. 252. 



Schizoporella inscttlpta Hincks, 1883, vol. 11, p. 447, pi. 17, fig. 



5, 5a. 



ScliizoporeUu inscuJpta, Eobertson, 1900, p. 326. 



Zoarium incrusting, or rising into foliaceous, bilaminate ex- 

 pansions. Zooecia large, elongated, alternate, separated by dis- 

 tinct lines: front wall thickly covered with large pores. Orifice 



