Biological results of the University of Miami deep-sea expeditions. 130. The systematics and zoogeography of the gastropod family Trochidae collected in the Straits of Florida and its approaches

MALACOLOGIA, 1979, 19(1): 1-62 BIOLOGICAL RESULTS OF THE UNIVERSITY OF MIAMI DEEP-SEA EXPEDITIONS. 130. THE SYSTEMATICS AND ZOOGEOGRAPHY OF THE GASTROPOD FAMILY TROCHIDAE COLLECTED IN THE STRAITS OF FLORIDA AND ITS APPROACHES James F. Quinn, Jr. Rosenstiel School of Marine and Atmospheric Sciences, University of Miami, 4600 Rickenbacker Causeway, Miami, FL 33149, U.S.A. ABSTRACT Fifty-four species of molluscs in the family Trochidae are reported from the Straits of Florida in depths of 180 m or more. The following new taxa are described: Echinogurges, n. gen. (type- species Trochus (Margarita) clavatus Watson); Mirachelus clinocnemus, n. sp.; Solariella (Solariella) multirestis, n. sp.; Microgaza rotella inornata, n. subsp. Microgaza vetula Woodring is reported from the Recent fauna for the first time. The radula of Microgaza rotella rotella Dall is described and illustrated for the first time and indicates that Microgaza is in the subfamily Solariellinae. Each species, except those in the genera Gaza, Calliostoma and Lischkeia, is fully described and illustrated with photographs, and synonymies and distributions are given. A Zoogeographie analysis indicates that the trochid fauna is a tropical deep-sea assemblage. INTRODUCTION The molluscan fauna of the Straits of Flor- ida has been extensively, if sporadically, sampled, beginning with the BLAKE expedi- tions (1877-78, 1878-79, 1880) and continu- ing to 1972, when the R/V GERDA was re- tired from service by the University of Miami. The identification of species from this area has been based primarily on the work of Willi- am Healey Dall (1881, 1889, 1927a,b). The majority of his work was excellent, but he often worked with scanty collections and in- adequate literature, and mistakes and dis- crepancies often appeared. Despite this, sub- sequent authors have generally accepted Dall's opinions uncritically, especially in the archaeogastropod family Trochidae. Since Dall, several descriptive works and a few faunal lists have included species found in the Straits, but except for a study of Gaza (Clench & Abbott, 1943) and a monograph of the genus Calliostoma (Clench & Turner, 1960), no critical work has been attempted involving trochids found in the Straits. Since the GERDA collections were rather rich in trochids, this study was selected to fill a con- siderable gap in the systematic literature of the Trochidae. This study treats those species of Trochi- dae which have been taken in depths greater than 180 m in the Straits of Florida and deals with the systematics and zoogeography of this rather important group. The depth limita- tion eliminates 1 1 shallow-water species from consideration in the systematic account, but for the sake of completeness, 1 of these are included in the Zoogeographie considerations. LITERATURE REVIEW OF STRAITS TROCHIDAE In the first hundred years after Linnaeus's 10th edition of Systema Naturae was pub- lished, 8 species of trochids assignable to the Straits fauna were described. Linnaeus (1758), Born (1778), Lamarck (1822) and Arthur Adams (1854) each described 1 spe- cies, and Gmelin (1791) and С