■452 NOTES ON PROSOBRANCHIATA, 



The species which are referred to Lotoriuniy Dall and Simpson 

 ( =- Cymatium, Tryon) ?ire—/emorale, Linn. ; tigrinus, Brod. ; 

 lotorium, Linn., pyrum, Linn.; dunkeri, Lischke; and miinsteri, 

 Anton. The difference between L. pyrum and L cynocephalum 

 is if avi^'thing, less than that between the former and L. lotorium. 

 It would, therefore, be unreasonable to separate generically 

 pyrtcm and cynocephalum. By the same argument we may include 

 first L. sarcofiioma, then L. trilineatum, Reeve; thence all the rest 

 of the species included in Tryon's Gutturnium. 



A series of species generically similar in every way, but with 

 gradually shortening canals, is formed by — sarcostoma, tripus, 

 aegrotus, vespaceus, thersites, crispus and quoyi. It would be 

 impossible to place any one in this series in one genus and either 

 of those next to it in another. They are all included in Tryon's 

 Gutturnhim. The same remarks maybe made of the series, with 

 gradually elongating canals, formed by doliarium, spengleri, 

 waterhouseij tranquebaricus, pilearis, mundum, gemmatus and 

 orientoJis. This series is placed by Tryon in Simpidum. The 

 resemblance between ye^nmatus and quoyi is very much greater 

 than between quoyi and sarcostoma. Again, crispus is more 

 nearly related to orientalis than orientalis is to spengleri. Another 

 line of generic similarity is — waterhousei, chemnitzi, succinctus, 

 cingulatus, connecting completely the tun-shaped species of 

 Tryon's group Linatella with Simpulum. Yet another perfect 

 series is presented by — verracosum, quoyi, intermedius, rmindum, 

 vespaceus, eraratus, chlorostoma, thersites, orientalis and crispus. 

 This is not merely a series but a complete ring, for crisjnis is 

 nearly related to verrucosum. Of this series Nos. 1, 2, 5, 6 and 8 

 are, according to Tryon's classification, referable to Ranularia. 

 Nos. 3, 4. 7, 9 and 10 to Lampusia. Lotorium tritonis is con- 

 nected, though not so perfectly, to the typical group by — nodiferus, 

 hassi, suhdistortus, tumidosus, philomelce,* oligostirus, eburneum, 

 quoyi, etc. 



* Watson, Chall. Eep. Zool. xv., p. 391, pi. xiv., f. 10 (1885). 



