1898.] NATURAL SCIENCES OF PHILADELPHIA. 253 



P. coeruleum Cockerell. PI. IX, figs. 7-11 ; PI. XI, fig. 30 ; PI. XIII, figs. 51-53 ; 

 PI. XVI, fig. 86. 



Prophvsaon coeruleum Cockerell, Nautilus, iii, p. 112. Ann. Mag. N. H. 

 (6), VI, p. 278. W. G. Binney, Third Suppl. T. M. V, p. 209, PI. vii, f. 

 I, J. 



P. coeruleum var. dubium Ckll., /. c. ; W. G. Binney, /. c. 



Length (in alcohol) about 15 mm. ; color blue or slate-blue (some- 

 times brown), somewhat paler at the sides. Back with close, deep 

 longitudinal grooves, which, on the sides, become oblique and more 

 spaced, and more anteriorly they radiate vertically below the man- 

 tle ; transverse grooves uniting the longitudinals comparatively few 

 and shallow. Foot-margin very narrow, a second narrow well- 

 defined sub-margin above it. Tail without caudal pore, frequently 

 self-amputated and leaving a conspicuous longitudinal slit (PI. IX, 

 fig. 7, and figs. 9-11, the excised portion). 20 



Genitalia (PI. XIII, fig. 51-53) somewhat as in P. Andersoni. 

 The epiphallus is short ; in one of the original specimens from Olym- 

 pia (PI. XIII, figs. 52, 53) very short, truncated at the ends ; in 

 another specimen from Seattle (PI. XIII, fig. 51) it is oblong ; vas 

 deferens tangled, but shorter than in Andersoni. Spermatheca 

 globular, on a rather slender duct, which is short in the Olympian 

 specimen, longer in that from Seattle. 



Radula about as in P. fasciatum ; the cusps of outer lateral and 

 inner marginal teeth rather short ; marginals quite wide (PI. XVI, 

 fig. 86). 



Type locality, Olympia, Washington (Hemphill). In addition to 

 part of Hemphill's original lot, we have received it from Seattle (P. 

 B. Randolph) and Portland, Oregon (J. G. Malone). Mr. Ran- 

 dolph writes that "it occurs solitary in dark fir woods under damp 

 logs. Color in life a brighter shade of blue. They do not bear 

 handling. " 



"P. coeruleum is an exceedingly distinct species, distinguished at 

 once by its color and the character of its reticulations." In the lat- 

 ter respect, the species differs from all others of the genus, and re- 



20 The original description from larger specimens than we have seen, is as fol- 

 lows : '' Length in (alcohol) 22A- mill., in motion 43 mill. Body and mantle 

 clear blue -gray, paler at sides, sole white. Mantle finely granulated, broad, 

 without markings. Length of mantle 7 mill.. breadth 5 mill. Respiratory 

 orifice 2J mill, from anterior border. Body subcylindrical, tapering, pointed. 

 ( In one specimen eaten off at the end. ) Distance from posterior end of man- 

 tle to end of body lOf mill. The reticulations take the form of longitudinal 

 equidistant lines, occasionally joined by transverse lines, or coalescing. Sole 

 not differentiated into tracts. Jaw pale, strongly ribbed. Liver white. Mr. 

 Binney sends me colored drawings of the living animal ; the neck is long and 

 white, or very pale." 



