132 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 



16. Zooecia slender, curved, spines very long spinigera 



Zooecia stout, closely set; joint across proximal half of outer 



zooecium 17 



17. Frontal avicularia all small, somewhat elevated, mandible tri- 



angular ; scutum with retrorse points at the basal corners. 



regularis 



Frontal avicularia more compressed and elevated, especially 

 the larger one on the axial zooecium, mandible narrow; 



scutum with broadly wedge-shaped base obtecta 



Scrupocellaria pugnax. This species was accidentally omitted in the 

 key. It works out at 5, frontal avicularia large and transverse, lateral 

 avicularia wanting. 



As additional aid in identifying the many species of Scrupocellaria 

 the following grouping according to certain characters will be found 

 useful. 

 Two axial vibracula: 5. har?neri Osburn, S. profundis n. sp., S. scru- 



posa (L.). 

 Vibracular groove more or less transverse: S. bertholetti (Audouin), S. 



h. tenuirostris n. van, S. scabra (van Beneden), S. varians Hincks, 



S. panamensis n. sp., S. talonis, n. sp. 

 Giant frontal avicularia: S. bertholetti (Audouin), S. b. tenuirostris 



n. van, S. ferox Busk, S. pugnax n. sp. 

 Giant lateral avicularia: S. bertholetti (Audouin), S. unguiculata n. sp., 



S. varians Hincks, S. talonis n. sp., S. californica Trask (but 



normal in form). 

 Scutum forked: S. bertholetti (Audouin), S. panamensis n. sp., S. varians 



Hincks, S. b. tenuirostris n. van 

 Scutum oval, without cervicorn decorations : S. californica Trask, S. di- 



egensis Robertson, S. harmeri Osburn. 

 Scutum wanting: S. ferox Busk, S. profundis n. sp., S. scruposa (L), 



S. pugnax n. sp., S. talonis n. sp. (or vestigial). 

 Ovicell imperforate: S. californica Trask, S. harmeri n. sp., S. scabra 



(van Beneden), S. scruposa (L.), S. varians Hincks. 



Even with this additional grouping of characters identification is not 

 always easy because of variation. Giant avicularia may be a dominant 

 feature, or they may be comparatively rare in the same species. The shape 

 and size of the scutum and the number and size of the spines are subject 

 to much variation. Ovicells are wanting in colonies that have not reached 

 reproduction. The vibracular chamber appears to vary less than other 

 structures. 



