STROPHALOSIA. 47 



Cancrini, I readily recognize as belonging to S. Morrisiana." Again, in his paper in the 

 ' Annals' for March and April, 1856, Professor King observes — " I suspect all the speci- 

 mens described and figured by Geinitz as Orthotrix lamettosus and Prod. Cancrini belong 

 to var. Humbletonensis." From the above it is evident that Professor King suspected 

 Stroph. Morrisiana and lamettosus to be synonymous, but from not being cognizant 

 with Geinitz's priority, had placed the German author's name among the synonyms of 

 his own. Baron Schauroth, in his late publication, considers S. lamellosa a variety of 

 Morrisiana ; and Mr. Howse is now strongly convinced that the two are synonymous. 



Strop/iaiosia Morrisiana has been several times confounded with Productus Cancrini, 

 a shell not only specifically but generically distinct. In 1855, Professor M'Coy felt 

 confident as to King's species being a synonym of Cancrini, which opinion was also repro- 

 duced in January, 1847, by Mr. Howse; and Professor De Koninck was strongly biassed 

 towards a similar conclusion. Professor King, on the contrary, has always maintained 

 that both were distinct although closely related species. 



In order to arrive at a positive conclusion, I obtained from Dr. Schrenk, through the 

 mediation of Count A. von Keyserling, a perfect example of the Russian P. Cancrini, 

 brought from Usty Joshuga, near Archangel (see woodcut in p. 48), and for which kindness 

 I feel much indebted to my two Russian friends. On its arrival in England, I lost no time 

 in submitting the specimen to the attentive examination of Professor King, Mr. Howse, and 

 Mr. Kirkby, and they all agreed with me that it was a true Productus, while Geinitz's 

 lamettosus and King's Morrisiana belonged to the genus Strophalosia, these shells differing 

 in every particular except in that of the striae, a character that appears to have been the 

 source of all the mistaken identifications. 



Productus Cancrini may be at once distinguished from all the varieties of Strophalosia 

 lamellosa by its total absence of area and denticulated hinge ■} for although the first is 

 small and scarcely perceptible, on account of the incurvation of the beak, in the larger 

 number of Strophalosia lamellosa, var. Humbletonensis, it is clearly visible ; the hinge-line, 

 which in the last is comparatively much shorter, is also distinctly articulated by the means 

 of teeth and sockets ; it differs also in general character, the spines on the back of the 

 larger valve in P. Cancrini do not appear to have been so long, adpressed, or creeping, as 

 in St. lamellosa and its varieties, and the numerous erect cardinal spines are altogether 



1 In order to facilitate comparison, I have here described the Russian example of Productus Cancrini, 

 kindly forwarded by Dr. Schrenk and Count Keyserling : 



Productus Cancrini, Murch. De Verneuil and De Keyserling, Russsia and the Oural 

 Mountains, vol. ii, p. 273, pi. xvi, fig. 8 a, b ; pi. xviii, fig. 7 

 1845. 

 — — De Koninck. Monographie du genre Productus, p. 105, pi. xi> 



fig. 3, 1847. 



Shell concavo-convex, as wide as long, slightly transverse or elongated, and rarely exceeding one inch 



