304 MARGARITA. 



I am haunted with the impression of having somewhere seen this 

 species, hut can come on no more definite remembrance of it. It is 

 connected with the Trochus ottoi, Phil., group, and is not remote 

 from Trochus (Margarita) infundibulum W., but is quite certainly 

 distinct. 



It may be observed that I have put a mark of interrogation to the 

 station whence this species comes. The solitary specimen had been 

 sent to Mr. Henderson that he might deal with the Pagurus it con- 

 tained. Mr. Henderson in handing it to me, expressed some doubt 

 of the accuracy of the station marking, as the Pugurus living in the 

 shell was a North Atlantic species. The Trochus itself also suggests 

 to me that locality rather than the shallow water of a South Pacific 

 locality like station 304. ( Watson.) 



North-west Patagonia, 45 fms. 



T. (Margarita) illotus WATSON, Challenger Kept., Gasterop., p. 

 86, t. 17, f. 3. 



M. STREPTOPHORUS Watson. PL 64, figs. 65, 66. 



Shell ivory white, thin, conical, rounded at the periphery, um- 

 bilicated, sculptured, and rough on the upper whorl. Sculpture : 

 The upper whorls are dull, rough, reticulated, being crossed by 

 oblique close-set riblets, scored by 7 or 8 fine round threads ; the 

 riblets gradually degenerate into puckerings, which die out in the 

 course of the penultimate whorl ; a necklace of little tubercles near 

 the top of the puckerings becomes on this whorl double or treble, 

 the tubercles being at the same time horizontally elongated ; in 

 this whorl too a very obtuse feeble tubercled carination appears in 

 the middle of the whorls; both this keel and the subsutural neck- 

 lace die out toward the mouth ; the edge of the umbilicus is 

 angularly keeled ; outside of the keel is a strongish, but depressed 

 thread ; besides this stronger sculpture the whole surface is scored 

 with very fine lines of growth and still more microscopic spiral 

 scratches. Color white, dead above, and with the gloss and beauty 

 of ivory below, where a faint pearly nacre gleams through. Spire 

 somewhat raised, scalar. Apex small mammillated, but prominent. 

 Whorls 61, high and convex, more or less angulated above the 

 periphery, of regular but rapid increase ; the last large, with a 

 round but slightly flattened base, and with a large marginated 

 funnel-shaped umbilicus, within which the lines of growth are very 

 strong. Suture strong marginated. Mouth largish, round. Outer 

 lip thin beveled off from the inside to a sharp edge, nacreous 



