﻿DALL] REV1KW OF FROG-SHELLS AND TRITONS I -9 



somewhat twisted when not functioning. The peduncles of the i 

 are fused with the tentacles externally so that the eyes appear to be 

 sessile on the latter some distance above the tentacular base. The 

 proboscis is stout and retractile. The ovicapsules are deposited on 

 shells, stones, etc., in moderate depths of water. They occur, asso- 

 ciated in groups, though each capsule is separately placed, being 

 usually urn-shaped or prismatic in form, taller than wide, and with a 

 flat marginated top, through which the young issue. The capsules of 

 Ranella {calif ornica) are somewhat similar, but wider than high, 

 and shaped (except for the flat top) somewhat like a thick slice of 

 bread from a square loaf. 



According to Krebs, in the West Indies Septa is found in twelve 

 feet of water among seaweeds; CymaHum (femorale) on blue sandy 

 mud near low-water mark; and such species as T. tuberosum, labi- 

 osunt, and pileare in two or three feet of water among stones and 

 coral. Colubraria (lanceolata) affects similar situations. The 

 Ranellas of the West American coast appear (R. calif ornica) in 

 immense numbers in shallow water to spawn, at times, but not every 

 year; and after spawning they return to depths of ten or fifteen 

 fathoms. The tropical species, at Panama and elsewhere, are dredged 

 in fifteen to forty fathoms. Distortrix on the same coast is obtained 

 in ten to over fifty fathoms, but in the Antilles has been dredged 

 living in more than one hundred and fifty fathoms. Indeed the 

 shallow water situs recorded by Krebs may be merely the limit 

 reached in spawning by many Tritons which live, as shown by the 

 Blake dredgings, at times in depths nearly reaching one hundred and 

 fifty fathoms and even more. On the Alaskan coast I have dredged 

 Fusitriton oregonensis in four to six fathoms, but the Albatross has 

 obtained it in depths down to one hundred and sixty fathoms. It 

 seems to prefer a mud and gravel bottom, and is almost invariably 

 decollate or eroded at the apex. I have never seen an adult retaining 

 the earlier whorls intact. The Magellanic species also occurs in 

 depths down to sixty fathoms. In general the animals of this group 

 have their soft parts brilliantly colored, often with ocellated mark- 

 ings, the colors being variable in the individuals of a single species. 

 Septa is an exception, the animal, in contrast to the shell, being, in 

 all the observed species, relatively dull-colored and without delimited 

 spots or ocelli. Couthouy thought the colors were distributed sex- 

 ually within the species, but this was probably accidental in the cases 

 he observed, as I have found no uniformity of this sort in the Alaskan 

 species. 



Accepting Troschel's division of the groups under consideration 



