^fl31 Mtcliatl: Sdfjitla (■(illfoniiea fraiii Snii Diffjo Eegioii 91 



conspicuously. On a black backgi'ound the head, intestine, ven- 

 tral ganglion, ovaries, and seminal vesicles appear much more 

 opaque than the body proper which, like the tail, is translucent, 

 nearly semi-opaque. The lateral fins, as well as tail-fin, are 

 readily recognized as very transparent areas in decided contrast 

 to the body. In degree of opacity .S'. californica resembles S. 

 serratodcntata more than any other species, although it is more 

 translucent than is the latter. 



The presence of numerous tactile hairs (pi. 2, fig. 1) extend- 

 ing from head to seminal vesicles, reveals, to the naked eye, a 

 pronounced serrated appearance, especially between the head and 

 ventral ganglion. These hairs occur most abundantly along the 

 anterior half of the collarette. In older individuals, from four 

 to twelve may be present on each of the paired fins and on the 

 tail-fin. These hairs, like those in i?. bipimctata and other species, 

 are rendered much less conspicuous after long preservation in 

 either alcohol or formalin. 



Char.\cters. — Body very firm and rigid, retaining its form 

 almost perfectly. Neck and constriction at tail-septinii promi- 

 nent, but rendered inconspicuous by the collarette. Body slightly 

 widest throughout middle third, tapering very gradually toward 

 head and tail. Lateral fields small. Muscles thick and strong. 

 Corona ciliata not observed. 



CoUarctfe (pi. 2, fig. 1), mas.sive and very long, extending 

 from head to tail-septum, and thence to seminal vesicles. Broad- 

 est just behind head (13-14 per cent of maximum body-width), 

 gradually narrowing caudally until, opposite the posterior end 

 of anterior fins, it is only about 3 per cent of the maximum 

 body-width. From here it may vary slightly in width until it 

 disappears at the tail-septum. Behind this structure, the col- 

 larette reappears and broadens regularly until it attains a width 

 of about 12 per cent directly anterior of the seminal vesicles. 

 It then very abruptly uan-ows, disappearing entirely at the 

 vesicles. 



Anterior fin shorter and narrower than posterior fin, varying 

 in length from 16.5 to 21.8, and in width from 1.65 to 3.35 per 

 cent of total length of animal. It approaches closely to but does 

 not reach the ventral ganglion, the interval varying from 0.76 



