690 



PROCEEDINGS OE THE NATIONAL MUSEUM. 



VOL. XXXV. 



The abundance and excellent state of preservation of the material 

 of this species in the collection of the Hopkins Laboratory at Pacific 

 Grove, and the fact that this material was kindly placed at the dis- 

 position of the writer for study, and, so far as necessary, for dissection; 

 together with the typical nature of this pennatulid and the apparent 

 absence of any even fairly complete account of the anatomy of any 

 member of the order published in English, have induced the writer to 

 seize the opportunity to make a fairly exhaustive study of this 

 species and a representation of its anatomy by the use of photography. 



One of the first facts brought to light in the study of this material is 

 the remarkable variation in size, color, and number of leaves, as is 

 shown in the following table : 



It is evident that the proportionate length of stem to rachis is 

 exceedingly variable, one specimen having a stem 6 inches long and 

 rachis 22.5 inches, while another (No. 7) has the rachis longer than 

 the stem. This is doubtless due to the fact that the stem is com- 

 posed largely of a tissue that is truly erectile, so that the length of an 

 individual stem will vary greatly at different times. The method of 

 killing and the state of expansion at death will largely determine the 

 length of the specimen. 



The violet color seems, at first sight, to be due to sexual maturity; 

 but there are in the collection of the University of California three 

 specimens taken near Pacific Grove averaging only a little over 2 

 inches in length, which have but 16 pairs of leaves, and which I can 

 not < liil'erentiate from this species. Their color is light-pinkish purple, 

 the stem being a dull dark red, but yellow at the end.' Two of these 

 specimens are illustrated by fig. 9 on Plate LXXXIY. 



There are two specimens showing irregularities or abnormalities. 



NO. 7 has a new leaf intercalated between two old ones, and a small 

 l.at' is growing directly from the upper Hat surface of a, fully-developed 

 one. 



" This fad is well known to the local Chinese fishermen, who secure (his species on 

 their trawl lines, and have a name for the species l>ase<l on this character. 



