1902.] NATURAL SCIENCES OF PHILADELPHIA. 73 



"Frontal grooves double, oblique, the outer interrupted." With 

 the obliquity an extension has taken place on to the epistonia. The 

 external groove is really not developed, on account of the non- 

 extension of the toxese. The setigerous punctures of the epistonia 

 are within the anterior extremities of the developing external 

 grooves, while the other punctures are within fovese, as in figs. 2 and 

 8, the extension of the fovese being not developed. Ocular bead 

 and sulcus normal. 



Figs. 4 and 9, Group XVII, B. anguliferum and B. assiinile. 

 The former drawn from a specimen in the Van Dyke collection, 

 and collected in Lake county, Cal. ; the latter species from a speci- 

 men taken in Ohio. 



"Frontal grooves very deep, strongly convergent, double, the inner 

 groove long, the order shorter and often feebly marked." Ridges 

 strongly developed and very convex. Here is a stronger tendency 

 for the fovese to coalesce ; it can be seen that the foveae on epistoma 

 are elongate, the splitting of the ridges being more evident. The 

 internal groove is strongly developed and entire ; ocular beads not 

 developed at margins of the eyes, but present on outer borders of 

 frontal processes ; ocular sulcus feeble but normal. 



Figs. 7 and 1, Group XVI, B. concinnum n. sp. and B. sulca- 

 tum. The former collected by Dr. Van Dyke in Eldorado coimty, 

 Cal. ; the latter species was taken in the Caraboo District, B. C, 

 and is in the Fuchs collection. 



"Frontal grooves double, scarcely (to moderately) converging, the 

 outer entire " (or nearly so). 



I have placed concinnum in the present group on accoimt of the 

 frontal grooves moderately converging, and also from the greater 

 tendency toward the development of the external groove, by the 

 appearance of intermediate fovese betAveen those of the punctures of 

 the epistoma and those of the anterior supraorbital punctures. 

 The internal groove is well developed ; ocular bead and sulcus 

 normal. 



In sulcatum the full development is reached — the internal and 

 external grooves are entire ; the internal ridges are entire, the 

 external being bifurcate to receive the posterior supraorbital punc- 

 tures. Ocular bead entire ; the ocular sulcus broad and normal in 

 extent. 



