29 
6. À new species of Polycystid Gregarine from the United States. 
By Max M. Ellis, 
Instructor in Biology, University of Colorado. 
(With 2 figures.) 
eingeg. 5. November 1911. 
The material from which this gregarine was taken, was collected 
in and around the city of Boulder, Colorado, during the months of 
September and October, 1911. Tenebrionid beetles of the genus Ele- 
odes are very abundant in this vicinity and as the gregarines were found 
in great numbers in about ninety percent of the specimens examined, 
Stylocephalus giganteus is to be regarded as one of the most abundant 
gregarines of this region. The gregarines were studied alive in normal 
salt solution and after being properly killed, in alcohol. The figures 
are from camera lucida drawings of living specimens. 
While working on this species, Prof. T. D. A. Cockerell kindly 
called my attention to the fact that the name Stylorhynchus as applied 
to the genus Stylorhynchus Stein, 1848, was preoccupied by Stylo- 
rhynchus Lesson, 1847, in Aves. As the new gregarine was referred 
to the genus of Stein, two important changes in the existing nomen- 
clature were made necessary. The name Stylocephalus is substituted 
for the genus Stylorhynchus Stein, and Stylocephalidae for the family . 
Stylorhynchidae A. Schneider, 1886, which is rendered invalid by 
the change of the generic name. 
Stylocephalidae fam. nov. — Stylorhynchidae A. Schneider, 1886. 
Stylocephalus genus nov. — Stylorhynchus Stein, 1848, 
Stylocephalus giganteus sp. nov. 
Type, 1500 «, Boulder, Colorado, U.S.A. (Ser. No. 1.) 
Cotypes, 214—1825 «, Boulder, Colorado. (University of Colorado.) 
Average specimens, 1200—1800 w, maximum 2135 u. 
Host, Eleodes sp., a Tenebrionid. 
Infection, about 90% ; individuals abundant. 
Habitat, mesenteron, and to a less extent the proctodaeum. 
Length of the protomerite from 1,1 to 2,1, (average, 1,5), in the 
length of the epimerite, and 9,75 to 18,3 in the total length of the gre- 
garine without the epimerite; maximum width of the protomerite 1 to 
1,5 in the maximum width of the deutomerite; maximum width of the 
deutomerite 7 to 12 in the total length without the epimerite. 
Epimerite long and pointed; basal half to two-thirds, cylindrical 
often becoming rather globose just before the epimerite is cast off; apical 
portion quite rugose, consisting of a small, slightly expanded part and 
